@commercetools/sdk-middleware-auth/dist/sdk-middleware-auth.umd.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
  typeof define === 'function' && define.amd ? define(['exports'], factory) :
  (global = global || self, factory(global.CommercetoolsSdkMiddlewareAuth = {}));
}(this, (function (exports) { 'use strict';

  function _defineProperty(obj, key, value) {
    if (key in obj) {
      Object.defineProperty(obj, key, {
        value: value,
        enumerable: true,
        configurable: true,
        writable: true
      });
    } else {
      obj[key] = value;
    }

    return obj;
  }

  function ownKeys(object, enumerableOnly) {
    var keys = Object.keys(object);

    if (Object.getOwnPropertySymbols) {
      var symbols = Object.getOwnPropertySymbols(object);
      if (enumerableOnly) symbols = symbols.filter(function (sym) {
        return Object.getOwnPropertyDescriptor(object, sym).enumerable;
      });
      keys.push.apply(keys, symbols);
    }

    return keys;
  }

  function _objectSpread2(target) {
    for (var i = 1; i < arguments.length; i++) {
      var source = arguments[i] != null ? arguments[i] : {};

      if (i % 2) {
        ownKeys(Object(source), true).forEach(function (key) {
          _defineProperty(target, key, source[key]);
        });
      } else if (Object.getOwnPropertyDescriptors) {
        Object.defineProperties(target, Object.getOwnPropertyDescriptors(source));
      } else {
        ownKeys(Object(source)).forEach(function (key) {
          Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key));
        });
      }
    }

    return target;
  }

  var global$1 = typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {};

  var lookup = [];
  var revLookup = [];
  var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
  var inited = false;

  function init() {
    inited = true;
    var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

    for (var i = 0, len = code.length; i < len; ++i) {
      lookup[i] = code[i];
      revLookup[code.charCodeAt(i)] = i;
    }

    revLookup['-'.charCodeAt(0)] = 62;
    revLookup['_'.charCodeAt(0)] = 63;
  }

  function toByteArray(b64) {
    if (!inited) {
      init();
    }

    var i, j, l, tmp, placeHolders, arr;
    var len = b64.length;

    if (len % 4 > 0) {
      throw new Error('Invalid string. Length must be a multiple of 4');
    } // the number of equal signs (place holders)
    // if there are two placeholders, than the two characters before it
    // represent one byte
    // if there is only one, then the three characters before it represent 2 bytes
    // this is just a cheap hack to not do indexOf twice


    placeHolders = b64[len - 2] === '=' ? 2 : b64[len - 1] === '=' ? 1 : 0; // base64 is 4/3 + up to two characters of the original data

    arr = new Arr(len * 3 / 4 - placeHolders); // if there are placeholders, only get up to the last complete 4 chars

    l = placeHolders > 0 ? len - 4 : len;
    var L = 0;

    for (i = 0, j = 0; i < l; i += 4, j += 3) {
      tmp = revLookup[b64.charCodeAt(i)] << 18 | revLookup[b64.charCodeAt(i + 1)] << 12 | revLookup[b64.charCodeAt(i + 2)] << 6 | revLookup[b64.charCodeAt(i + 3)];
      arr[L++] = tmp >> 16 & 0xFF;
      arr[L++] = tmp >> 8 & 0xFF;
      arr[L++] = tmp & 0xFF;
    }

    if (placeHolders === 2) {
      tmp = revLookup[b64.charCodeAt(i)] << 2 | revLookup[b64.charCodeAt(i + 1)] >> 4;
      arr[L++] = tmp & 0xFF;
    } else if (placeHolders === 1) {
      tmp = revLookup[b64.charCodeAt(i)] << 10 | revLookup[b64.charCodeAt(i + 1)] << 4 | revLookup[b64.charCodeAt(i + 2)] >> 2;
      arr[L++] = tmp >> 8 & 0xFF;
      arr[L++] = tmp & 0xFF;
    }

    return arr;
  }

  function tripletToBase64(num) {
    return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F];
  }

  function encodeChunk(uint8, start, end) {
    var tmp;
    var output = [];

    for (var i = start; i < end; i += 3) {
      tmp = (uint8[i] << 16) + (uint8[i + 1] << 8) + uint8[i + 2];
      output.push(tripletToBase64(tmp));
    }

    return output.join('');
  }

  function fromByteArray(uint8) {
    if (!inited) {
      init();
    }

    var tmp;
    var len = uint8.length;
    var extraBytes = len % 3; // if we have 1 byte left, pad 2 bytes

    var output = '';
    var parts = [];
    var maxChunkLength = 16383; // must be multiple of 3
    // go through the array every three bytes, we'll deal with trailing stuff later

    for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
      parts.push(encodeChunk(uint8, i, i + maxChunkLength > len2 ? len2 : i + maxChunkLength));
    } // pad the end with zeros, but make sure to not forget the extra bytes


    if (extraBytes === 1) {
      tmp = uint8[len - 1];
      output += lookup[tmp >> 2];
      output += lookup[tmp << 4 & 0x3F];
      output += '==';
    } else if (extraBytes === 2) {
      tmp = (uint8[len - 2] << 8) + uint8[len - 1];
      output += lookup[tmp >> 10];
      output += lookup[tmp >> 4 & 0x3F];
      output += lookup[tmp << 2 & 0x3F];
      output += '=';
    }

    parts.push(output);
    return parts.join('');
  }

  function read(buffer, offset, isLE, mLen, nBytes) {
    var e, m;
    var eLen = nBytes * 8 - mLen - 1;
    var eMax = (1 << eLen) - 1;
    var eBias = eMax >> 1;
    var nBits = -7;
    var i = isLE ? nBytes - 1 : 0;
    var d = isLE ? -1 : 1;
    var s = buffer[offset + i];
    i += d;
    e = s & (1 << -nBits) - 1;
    s >>= -nBits;
    nBits += eLen;

    for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8) {}

    m = e & (1 << -nBits) - 1;
    e >>= -nBits;
    nBits += mLen;

    for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8) {}

    if (e === 0) {
      e = 1 - eBias;
    } else if (e === eMax) {
      return m ? NaN : (s ? -1 : 1) * Infinity;
    } else {
      m = m + Math.pow(2, mLen);
      e = e - eBias;
    }

    return (s ? -1 : 1) * m * Math.pow(2, e - mLen);
  }
  function write(buffer, value, offset, isLE, mLen, nBytes) {
    var e, m, c;
    var eLen = nBytes * 8 - mLen - 1;
    var eMax = (1 << eLen) - 1;
    var eBias = eMax >> 1;
    var rt = mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0;
    var i = isLE ? 0 : nBytes - 1;
    var d = isLE ? 1 : -1;
    var s = value < 0 || value === 0 && 1 / value < 0 ? 1 : 0;
    value = Math.abs(value);

    if (isNaN(value) || value === Infinity) {
      m = isNaN(value) ? 1 : 0;
      e = eMax;
    } else {
      e = Math.floor(Math.log(value) / Math.LN2);

      if (value * (c = Math.pow(2, -e)) < 1) {
        e--;
        c *= 2;
      }

      if (e + eBias >= 1) {
        value += rt / c;
      } else {
        value += rt * Math.pow(2, 1 - eBias);
      }

      if (value * c >= 2) {
        e++;
        c /= 2;
      }

      if (e + eBias >= eMax) {
        m = 0;
        e = eMax;
      } else if (e + eBias >= 1) {
        m = (value * c - 1) * Math.pow(2, mLen);
        e = e + eBias;
      } else {
        m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen);
        e = 0;
      }
    }

    for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {}

    e = e << mLen | m;
    eLen += mLen;

    for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {}

    buffer[offset + i - d] |= s * 128;
  }

  var toString = {}.toString;
  var isArray = Array.isArray || function (arr) {
    return toString.call(arr) == '[object Array]';
  };

  var INSPECT_MAX_BYTES = 50;
  /**
   * If `Buffer.TYPED_ARRAY_SUPPORT`:
   *   === true    Use Uint8Array implementation (fastest)
   *   === false   Use Object implementation (most compatible, even IE6)
   *
   * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
   * Opera 11.6+, iOS 4.2+.
   *
   * Due to various browser bugs, sometimes the Object implementation will be used even
   * when the browser supports typed arrays.
   *
   * Note:
   *
   *   - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances,
   *     See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438.
   *
   *   - Chrome 9-10 is missing the `TypedArray.prototype.subarray` function.
   *
   *   - IE10 has a broken `TypedArray.prototype.subarray` function which returns arrays of
   *     incorrect length in some situations.

   * We detect these buggy browsers and set `Buffer.TYPED_ARRAY_SUPPORT` to `false` so they
   * get the Object implementation, which is slower but behaves correctly.
   */

  Buffer.TYPED_ARRAY_SUPPORT = global$1.TYPED_ARRAY_SUPPORT !== undefined ? global$1.TYPED_ARRAY_SUPPORT : true;

  function kMaxLength() {
    return Buffer.TYPED_ARRAY_SUPPORT ? 0x7fffffff : 0x3fffffff;
  }

  function createBuffer(that, length) {
    if (kMaxLength() < length) {
      throw new RangeError('Invalid typed array length');
    }

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      // Return an augmented `Uint8Array` instance, for best performance
      that = new Uint8Array(length);
      that.__proto__ = Buffer.prototype;
    } else {
      // Fallback: Return an object instance of the Buffer class
      if (that === null) {
        that = new Buffer(length);
      }

      that.length = length;
    }

    return that;
  }
  /**
   * The Buffer constructor returns instances of `Uint8Array` that have their
   * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
   * `Uint8Array`, so the returned instances will have all the node `Buffer` methods
   * and the `Uint8Array` methods. Square bracket notation works as expected -- it
   * returns a single octet.
   *
   * The `Uint8Array` prototype remains unmodified.
   */


  function Buffer(arg, encodingOrOffset, length) {
    if (!Buffer.TYPED_ARRAY_SUPPORT && !(this instanceof Buffer)) {
      return new Buffer(arg, encodingOrOffset, length);
    } // Common case.


    if (typeof arg === 'number') {
      if (typeof encodingOrOffset === 'string') {
        throw new Error('If encoding is specified then the first argument must be a string');
      }

      return allocUnsafe(this, arg);
    }

    return from(this, arg, encodingOrOffset, length);
  }
  Buffer.poolSize = 8192; // not used by this implementation
  // TODO: Legacy, not needed anymore. Remove in next major version.

  Buffer._augment = function (arr) {
    arr.__proto__ = Buffer.prototype;
    return arr;
  };

  function from(that, value, encodingOrOffset, length) {
    if (typeof value === 'number') {
      throw new TypeError('"value" argument must not be a number');
    }

    if (typeof ArrayBuffer !== 'undefined' && value instanceof ArrayBuffer) {
      return fromArrayBuffer(that, value, encodingOrOffset, length);
    }

    if (typeof value === 'string') {
      return fromString(that, value, encodingOrOffset);
    }

    return fromObject(that, value);
  }
  /**
   * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
   * if value is a number.
   * Buffer.from(str[, encoding])
   * Buffer.from(array)
   * Buffer.from(buffer)
   * Buffer.from(arrayBuffer[, byteOffset[, length]])
   **/


  Buffer.from = function (value, encodingOrOffset, length) {
    return from(null, value, encodingOrOffset, length);
  };

  if (Buffer.TYPED_ARRAY_SUPPORT) {
    Buffer.prototype.__proto__ = Uint8Array.prototype;
    Buffer.__proto__ = Uint8Array;
  }

  function assertSize(size) {
    if (typeof size !== 'number') {
      throw new TypeError('"size" argument must be a number');
    } else if (size < 0) {
      throw new RangeError('"size" argument must not be negative');
    }
  }

  function alloc(that, size, fill, encoding) {
    assertSize(size);

    if (size <= 0) {
      return createBuffer(that, size);
    }

    if (fill !== undefined) {
      // Only pay attention to encoding if it's a string. This
      // prevents accidentally sending in a number that would
      // be interpretted as a start offset.
      return typeof encoding === 'string' ? createBuffer(that, size).fill(fill, encoding) : createBuffer(that, size).fill(fill);
    }

    return createBuffer(that, size);
  }
  /**
   * Creates a new filled Buffer instance.
   * alloc(size[, fill[, encoding]])
   **/


  Buffer.alloc = function (size, fill, encoding) {
    return alloc(null, size, fill, encoding);
  };

  function allocUnsafe(that, size) {
    assertSize(size);
    that = createBuffer(that, size < 0 ? 0 : checked(size) | 0);

    if (!Buffer.TYPED_ARRAY_SUPPORT) {
      for (var i = 0; i < size; ++i) {
        that[i] = 0;
      }
    }

    return that;
  }
  /**
   * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
   * */


  Buffer.allocUnsafe = function (size) {
    return allocUnsafe(null, size);
  };
  /**
   * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
   */


  Buffer.allocUnsafeSlow = function (size) {
    return allocUnsafe(null, size);
  };

  function fromString(that, string, encoding) {
    if (typeof encoding !== 'string' || encoding === '') {
      encoding = 'utf8';
    }

    if (!Buffer.isEncoding(encoding)) {
      throw new TypeError('"encoding" must be a valid string encoding');
    }

    var length = byteLength(string, encoding) | 0;
    that = createBuffer(that, length);
    var actual = that.write(string, encoding);

    if (actual !== length) {
      // Writing a hex string, for example, that contains invalid characters will
      // cause everything after the first invalid character to be ignored. (e.g.
      // 'abxxcd' will be treated as 'ab')
      that = that.slice(0, actual);
    }

    return that;
  }

  function fromArrayLike(that, array) {
    var length = array.length < 0 ? 0 : checked(array.length) | 0;
    that = createBuffer(that, length);

    for (var i = 0; i < length; i += 1) {
      that[i] = array[i] & 255;
    }

    return that;
  }

  function fromArrayBuffer(that, array, byteOffset, length) {
    array.byteLength; // this throws if `array` is not a valid ArrayBuffer

    if (byteOffset < 0 || array.byteLength < byteOffset) {
      throw new RangeError('\'offset\' is out of bounds');
    }

    if (array.byteLength < byteOffset + (length || 0)) {
      throw new RangeError('\'length\' is out of bounds');
    }

    if (byteOffset === undefined && length === undefined) {
      array = new Uint8Array(array);
    } else if (length === undefined) {
      array = new Uint8Array(array, byteOffset);
    } else {
      array = new Uint8Array(array, byteOffset, length);
    }

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      // Return an augmented `Uint8Array` instance, for best performance
      that = array;
      that.__proto__ = Buffer.prototype;
    } else {
      // Fallback: Return an object instance of the Buffer class
      that = fromArrayLike(that, array);
    }

    return that;
  }

  function fromObject(that, obj) {
    if (internalIsBuffer(obj)) {
      var len = checked(obj.length) | 0;
      that = createBuffer(that, len);

      if (that.length === 0) {
        return that;
      }

      obj.copy(that, 0, 0, len);
      return that;
    }

    if (obj) {
      if (typeof ArrayBuffer !== 'undefined' && obj.buffer instanceof ArrayBuffer || 'length' in obj) {
        if (typeof obj.length !== 'number' || isnan(obj.length)) {
          return createBuffer(that, 0);
        }

        return fromArrayLike(that, obj);
      }

      if (obj.type === 'Buffer' && isArray(obj.data)) {
        return fromArrayLike(that, obj.data);
      }
    }

    throw new TypeError('First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object.');
  }

  function checked(length) {
    // Note: cannot use `length < kMaxLength()` here because that fails when
    // length is NaN (which is otherwise coerced to zero.)
    if (length >= kMaxLength()) {
      throw new RangeError('Attempt to allocate Buffer larger than maximum ' + 'size: 0x' + kMaxLength().toString(16) + ' bytes');
    }

    return length | 0;
  }
  Buffer.isBuffer = isBuffer;

  function internalIsBuffer(b) {
    return !!(b != null && b._isBuffer);
  }

  Buffer.compare = function compare(a, b) {
    if (!internalIsBuffer(a) || !internalIsBuffer(b)) {
      throw new TypeError('Arguments must be Buffers');
    }

    if (a === b) return 0;
    var x = a.length;
    var y = b.length;

    for (var i = 0, len = Math.min(x, y); i < len; ++i) {
      if (a[i] !== b[i]) {
        x = a[i];
        y = b[i];
        break;
      }
    }

    if (x < y) return -1;
    if (y < x) return 1;
    return 0;
  };

  Buffer.isEncoding = function isEncoding(encoding) {
    switch (String(encoding).toLowerCase()) {
      case 'hex':
      case 'utf8':
      case 'utf-8':
      case 'ascii':
      case 'latin1':
      case 'binary':
      case 'base64':
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return true;

      default:
        return false;
    }
  };

  Buffer.concat = function concat(list, length) {
    if (!isArray(list)) {
      throw new TypeError('"list" argument must be an Array of Buffers');
    }

    if (list.length === 0) {
      return Buffer.alloc(0);
    }

    var i;

    if (length === undefined) {
      length = 0;

      for (i = 0; i < list.length; ++i) {
        length += list[i].length;
      }
    }

    var buffer = Buffer.allocUnsafe(length);
    var pos = 0;

    for (i = 0; i < list.length; ++i) {
      var buf = list[i];

      if (!internalIsBuffer(buf)) {
        throw new TypeError('"list" argument must be an Array of Buffers');
      }

      buf.copy(buffer, pos);
      pos += buf.length;
    }

    return buffer;
  };

  function byteLength(string, encoding) {
    if (internalIsBuffer(string)) {
      return string.length;
    }

    if (typeof ArrayBuffer !== 'undefined' && typeof ArrayBuffer.isView === 'function' && (ArrayBuffer.isView(string) || string instanceof ArrayBuffer)) {
      return string.byteLength;
    }

    if (typeof string !== 'string') {
      string = '' + string;
    }

    var len = string.length;
    if (len === 0) return 0; // Use a for loop to avoid recursion

    var loweredCase = false;

    for (;;) {
      switch (encoding) {
        case 'ascii':
        case 'latin1':
        case 'binary':
          return len;

        case 'utf8':
        case 'utf-8':
        case undefined:
          return utf8ToBytes(string).length;

        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return len * 2;

        case 'hex':
          return len >>> 1;

        case 'base64':
          return base64ToBytes(string).length;

        default:
          if (loweredCase) return utf8ToBytes(string).length; // assume utf8

          encoding = ('' + encoding).toLowerCase();
          loweredCase = true;
      }
    }
  }

  Buffer.byteLength = byteLength;

  function slowToString(encoding, start, end) {
    var loweredCase = false; // No need to verify that "this.length <= MAX_UINT32" since it's a read-only
    // property of a typed array.
    // This behaves neither like String nor Uint8Array in that we set start/end
    // to their upper/lower bounds if the value passed is out of range.
    // undefined is handled specially as per ECMA-262 6th Edition,
    // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.

    if (start === undefined || start < 0) {
      start = 0;
    } // Return early if start > this.length. Done here to prevent potential uint32
    // coercion fail below.


    if (start > this.length) {
      return '';
    }

    if (end === undefined || end > this.length) {
      end = this.length;
    }

    if (end <= 0) {
      return '';
    } // Force coersion to uint32. This will also coerce falsey/NaN values to 0.


    end >>>= 0;
    start >>>= 0;

    if (end <= start) {
      return '';
    }

    if (!encoding) encoding = 'utf8';

    while (true) {
      switch (encoding) {
        case 'hex':
          return hexSlice(this, start, end);

        case 'utf8':
        case 'utf-8':
          return utf8Slice(this, start, end);

        case 'ascii':
          return asciiSlice(this, start, end);

        case 'latin1':
        case 'binary':
          return latin1Slice(this, start, end);

        case 'base64':
          return base64Slice(this, start, end);

        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return utf16leSlice(this, start, end);

        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding);
          encoding = (encoding + '').toLowerCase();
          loweredCase = true;
      }
    }
  } // The property is used by `Buffer.isBuffer` and `is-buffer` (in Safari 5-7) to detect
  // Buffer instances.


  Buffer.prototype._isBuffer = true;

  function swap(b, n, m) {
    var i = b[n];
    b[n] = b[m];
    b[m] = i;
  }

  Buffer.prototype.swap16 = function swap16() {
    var len = this.length;

    if (len % 2 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 16-bits');
    }

    for (var i = 0; i < len; i += 2) {
      swap(this, i, i + 1);
    }

    return this;
  };

  Buffer.prototype.swap32 = function swap32() {
    var len = this.length;

    if (len % 4 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 32-bits');
    }

    for (var i = 0; i < len; i += 4) {
      swap(this, i, i + 3);
      swap(this, i + 1, i + 2);
    }

    return this;
  };

  Buffer.prototype.swap64 = function swap64() {
    var len = this.length;

    if (len % 8 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 64-bits');
    }

    for (var i = 0; i < len; i += 8) {
      swap(this, i, i + 7);
      swap(this, i + 1, i + 6);
      swap(this, i + 2, i + 5);
      swap(this, i + 3, i + 4);
    }

    return this;
  };

  Buffer.prototype.toString = function toString() {
    var length = this.length | 0;
    if (length === 0) return '';
    if (arguments.length === 0) return utf8Slice(this, 0, length);
    return slowToString.apply(this, arguments);
  };

  Buffer.prototype.equals = function equals(b) {
    if (!internalIsBuffer(b)) throw new TypeError('Argument must be a Buffer');
    if (this === b) return true;
    return Buffer.compare(this, b) === 0;
  };

  Buffer.prototype.inspect = function inspect() {
    var str = '';
    var max = INSPECT_MAX_BYTES;

    if (this.length > 0) {
      str = this.toString('hex', 0, max).match(/.{2}/g).join(' ');
      if (this.length > max) str += ' ... ';
    }

    return '<Buffer ' + str + '>';
  };

  Buffer.prototype.compare = function compare(target, start, end, thisStart, thisEnd) {
    if (!internalIsBuffer(target)) {
      throw new TypeError('Argument must be a Buffer');
    }

    if (start === undefined) {
      start = 0;
    }

    if (end === undefined) {
      end = target ? target.length : 0;
    }

    if (thisStart === undefined) {
      thisStart = 0;
    }

    if (thisEnd === undefined) {
      thisEnd = this.length;
    }

    if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
      throw new RangeError('out of range index');
    }

    if (thisStart >= thisEnd && start >= end) {
      return 0;
    }

    if (thisStart >= thisEnd) {
      return -1;
    }

    if (start >= end) {
      return 1;
    }

    start >>>= 0;
    end >>>= 0;
    thisStart >>>= 0;
    thisEnd >>>= 0;
    if (this === target) return 0;
    var x = thisEnd - thisStart;
    var y = end - start;
    var len = Math.min(x, y);
    var thisCopy = this.slice(thisStart, thisEnd);
    var targetCopy = target.slice(start, end);

    for (var i = 0; i < len; ++i) {
      if (thisCopy[i] !== targetCopy[i]) {
        x = thisCopy[i];
        y = targetCopy[i];
        break;
      }
    }

    if (x < y) return -1;
    if (y < x) return 1;
    return 0;
  }; // Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
  // OR the last index of `val` in `buffer` at offset <= `byteOffset`.
  //
  // Arguments:
  // - buffer - a Buffer to search
  // - val - a string, Buffer, or number
  // - byteOffset - an index into `buffer`; will be clamped to an int32
  // - encoding - an optional encoding, relevant is val is a string
  // - dir - true for indexOf, false for lastIndexOf


  function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir) {
    // Empty buffer means no match
    if (buffer.length === 0) return -1; // Normalize byteOffset

    if (typeof byteOffset === 'string') {
      encoding = byteOffset;
      byteOffset = 0;
    } else if (byteOffset > 0x7fffffff) {
      byteOffset = 0x7fffffff;
    } else if (byteOffset < -0x80000000) {
      byteOffset = -0x80000000;
    }

    byteOffset = +byteOffset; // Coerce to Number.

    if (isNaN(byteOffset)) {
      // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
      byteOffset = dir ? 0 : buffer.length - 1;
    } // Normalize byteOffset: negative offsets start from the end of the buffer


    if (byteOffset < 0) byteOffset = buffer.length + byteOffset;

    if (byteOffset >= buffer.length) {
      if (dir) return -1;else byteOffset = buffer.length - 1;
    } else if (byteOffset < 0) {
      if (dir) byteOffset = 0;else return -1;
    } // Normalize val


    if (typeof val === 'string') {
      val = Buffer.from(val, encoding);
    } // Finally, search either indexOf (if dir is true) or lastIndexOf


    if (internalIsBuffer(val)) {
      // Special case: looking for empty string/buffer always fails
      if (val.length === 0) {
        return -1;
      }

      return arrayIndexOf(buffer, val, byteOffset, encoding, dir);
    } else if (typeof val === 'number') {
      val = val & 0xFF; // Search for a byte value [0-255]

      if (Buffer.TYPED_ARRAY_SUPPORT && typeof Uint8Array.prototype.indexOf === 'function') {
        if (dir) {
          return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset);
        } else {
          return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset);
        }
      }

      return arrayIndexOf(buffer, [val], byteOffset, encoding, dir);
    }

    throw new TypeError('val must be string, number or Buffer');
  }

  function arrayIndexOf(arr, val, byteOffset, encoding, dir) {
    var indexSize = 1;
    var arrLength = arr.length;
    var valLength = val.length;

    if (encoding !== undefined) {
      encoding = String(encoding).toLowerCase();

      if (encoding === 'ucs2' || encoding === 'ucs-2' || encoding === 'utf16le' || encoding === 'utf-16le') {
        if (arr.length < 2 || val.length < 2) {
          return -1;
        }

        indexSize = 2;
        arrLength /= 2;
        valLength /= 2;
        byteOffset /= 2;
      }
    }

    function read(buf, i) {
      if (indexSize === 1) {
        return buf[i];
      } else {
        return buf.readUInt16BE(i * indexSize);
      }
    }

    var i;

    if (dir) {
      var foundIndex = -1;

      for (i = byteOffset; i < arrLength; i++) {
        if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
          if (foundIndex === -1) foundIndex = i;
          if (i - foundIndex + 1 === valLength) return foundIndex * indexSize;
        } else {
          if (foundIndex !== -1) i -= i - foundIndex;
          foundIndex = -1;
        }
      }
    } else {
      if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength;

      for (i = byteOffset; i >= 0; i--) {
        var found = true;

        for (var j = 0; j < valLength; j++) {
          if (read(arr, i + j) !== read(val, j)) {
            found = false;
            break;
          }
        }

        if (found) return i;
      }
    }

    return -1;
  }

  Buffer.prototype.includes = function includes(val, byteOffset, encoding) {
    return this.indexOf(val, byteOffset, encoding) !== -1;
  };

  Buffer.prototype.indexOf = function indexOf(val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, true);
  };

  Buffer.prototype.lastIndexOf = function lastIndexOf(val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, false);
  };

  function hexWrite(buf, string, offset, length) {
    offset = Number(offset) || 0;
    var remaining = buf.length - offset;

    if (!length) {
      length = remaining;
    } else {
      length = Number(length);

      if (length > remaining) {
        length = remaining;
      }
    } // must be an even number of digits


    var strLen = string.length;
    if (strLen % 2 !== 0) throw new TypeError('Invalid hex string');

    if (length > strLen / 2) {
      length = strLen / 2;
    }

    for (var i = 0; i < length; ++i) {
      var parsed = parseInt(string.substr(i * 2, 2), 16);
      if (isNaN(parsed)) return i;
      buf[offset + i] = parsed;
    }

    return i;
  }

  function utf8Write(buf, string, offset, length) {
    return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length);
  }

  function asciiWrite(buf, string, offset, length) {
    return blitBuffer(asciiToBytes(string), buf, offset, length);
  }

  function latin1Write(buf, string, offset, length) {
    return asciiWrite(buf, string, offset, length);
  }

  function base64Write(buf, string, offset, length) {
    return blitBuffer(base64ToBytes(string), buf, offset, length);
  }

  function ucs2Write(buf, string, offset, length) {
    return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length);
  }

  Buffer.prototype.write = function write(string, offset, length, encoding) {
    // Buffer#write(string)
    if (offset === undefined) {
      encoding = 'utf8';
      length = this.length;
      offset = 0; // Buffer#write(string, encoding)
    } else if (length === undefined && typeof offset === 'string') {
      encoding = offset;
      length = this.length;
      offset = 0; // Buffer#write(string, offset[, length][, encoding])
    } else if (isFinite(offset)) {
      offset = offset | 0;

      if (isFinite(length)) {
        length = length | 0;
        if (encoding === undefined) encoding = 'utf8';
      } else {
        encoding = length;
        length = undefined;
      } // legacy write(string, encoding, offset, length) - remove in v0.13

    } else {
      throw new Error('Buffer.write(string, encoding, offset[, length]) is no longer supported');
    }

    var remaining = this.length - offset;
    if (length === undefined || length > remaining) length = remaining;

    if (string.length > 0 && (length < 0 || offset < 0) || offset > this.length) {
      throw new RangeError('Attempt to write outside buffer bounds');
    }

    if (!encoding) encoding = 'utf8';
    var loweredCase = false;

    for (;;) {
      switch (encoding) {
        case 'hex':
          return hexWrite(this, string, offset, length);

        case 'utf8':
        case 'utf-8':
          return utf8Write(this, string, offset, length);

        case 'ascii':
          return asciiWrite(this, string, offset, length);

        case 'latin1':
        case 'binary':
          return latin1Write(this, string, offset, length);

        case 'base64':
          // Warning: maxLength not taken into account in base64Write
          return base64Write(this, string, offset, length);

        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return ucs2Write(this, string, offset, length);

        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding);
          encoding = ('' + encoding).toLowerCase();
          loweredCase = true;
      }
    }
  };

  Buffer.prototype.toJSON = function toJSON() {
    return {
      type: 'Buffer',
      data: Array.prototype.slice.call(this._arr || this, 0)
    };
  };

  function base64Slice(buf, start, end) {
    if (start === 0 && end === buf.length) {
      return fromByteArray(buf);
    } else {
      return fromByteArray(buf.slice(start, end));
    }
  }

  function utf8Slice(buf, start, end) {
    end = Math.min(buf.length, end);
    var res = [];
    var i = start;

    while (i < end) {
      var firstByte = buf[i];
      var codePoint = null;
      var bytesPerSequence = firstByte > 0xEF ? 4 : firstByte > 0xDF ? 3 : firstByte > 0xBF ? 2 : 1;

      if (i + bytesPerSequence <= end) {
        var secondByte, thirdByte, fourthByte, tempCodePoint;

        switch (bytesPerSequence) {
          case 1:
            if (firstByte < 0x80) {
              codePoint = firstByte;
            }

            break;

          case 2:
            secondByte = buf[i + 1];

            if ((secondByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0x1F) << 0x6 | secondByte & 0x3F;

              if (tempCodePoint > 0x7F) {
                codePoint = tempCodePoint;
              }
            }

            break;

          case 3:
            secondByte = buf[i + 1];
            thirdByte = buf[i + 2];

            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | thirdByte & 0x3F;

              if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
                codePoint = tempCodePoint;
              }
            }

            break;

          case 4:
            secondByte = buf[i + 1];
            thirdByte = buf[i + 2];
            fourthByte = buf[i + 3];

            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | fourthByte & 0x3F;

              if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
                codePoint = tempCodePoint;
              }
            }

        }
      }

      if (codePoint === null) {
        // we did not generate a valid codePoint so insert a
        // replacement char (U+FFFD) and advance only 1 byte
        codePoint = 0xFFFD;
        bytesPerSequence = 1;
      } else if (codePoint > 0xFFFF) {
        // encode to utf16 (surrogate pair dance)
        codePoint -= 0x10000;
        res.push(codePoint >>> 10 & 0x3FF | 0xD800);
        codePoint = 0xDC00 | codePoint & 0x3FF;
      }

      res.push(codePoint);
      i += bytesPerSequence;
    }

    return decodeCodePointsArray(res);
  } // Based on http://stackoverflow.com/a/22747272/680742, the browser with
  // the lowest limit is Chrome, with 0x10000 args.
  // We go 1 magnitude less, for safety


  var MAX_ARGUMENTS_LENGTH = 0x1000;

  function decodeCodePointsArray(codePoints) {
    var len = codePoints.length;

    if (len <= MAX_ARGUMENTS_LENGTH) {
      return String.fromCharCode.apply(String, codePoints); // avoid extra slice()
    } // Decode in chunks to avoid "call stack size exceeded".


    var res = '';
    var i = 0;

    while (i < len) {
      res += String.fromCharCode.apply(String, codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH));
    }

    return res;
  }

  function asciiSlice(buf, start, end) {
    var ret = '';
    end = Math.min(buf.length, end);

    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i] & 0x7F);
    }

    return ret;
  }

  function latin1Slice(buf, start, end) {
    var ret = '';
    end = Math.min(buf.length, end);

    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i]);
    }

    return ret;
  }

  function hexSlice(buf, start, end) {
    var len = buf.length;
    if (!start || start < 0) start = 0;
    if (!end || end < 0 || end > len) end = len;
    var out = '';

    for (var i = start; i < end; ++i) {
      out += toHex(buf[i]);
    }

    return out;
  }

  function utf16leSlice(buf, start, end) {
    var bytes = buf.slice(start, end);
    var res = '';

    for (var i = 0; i < bytes.length; i += 2) {
      res += String.fromCharCode(bytes[i] + bytes[i + 1] * 256);
    }

    return res;
  }

  Buffer.prototype.slice = function slice(start, end) {
    var len = this.length;
    start = ~~start;
    end = end === undefined ? len : ~~end;

    if (start < 0) {
      start += len;
      if (start < 0) start = 0;
    } else if (start > len) {
      start = len;
    }

    if (end < 0) {
      end += len;
      if (end < 0) end = 0;
    } else if (end > len) {
      end = len;
    }

    if (end < start) end = start;
    var newBuf;

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      newBuf = this.subarray(start, end);
      newBuf.__proto__ = Buffer.prototype;
    } else {
      var sliceLen = end - start;
      newBuf = new Buffer(sliceLen, undefined);

      for (var i = 0; i < sliceLen; ++i) {
        newBuf[i] = this[i + start];
      }
    }

    return newBuf;
  };
  /*
   * Need to make sure that buffer isn't trying to write out of bounds.
   */


  function checkOffset(offset, ext, length) {
    if (offset % 1 !== 0 || offset < 0) throw new RangeError('offset is not uint');
    if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length');
  }

  Buffer.prototype.readUIntLE = function readUIntLE(offset, byteLength, noAssert) {
    offset = offset | 0;
    byteLength = byteLength | 0;
    if (!noAssert) checkOffset(offset, byteLength, this.length);
    var val = this[offset];
    var mul = 1;
    var i = 0;

    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul;
    }

    return val;
  };

  Buffer.prototype.readUIntBE = function readUIntBE(offset, byteLength, noAssert) {
    offset = offset | 0;
    byteLength = byteLength | 0;

    if (!noAssert) {
      checkOffset(offset, byteLength, this.length);
    }

    var val = this[offset + --byteLength];
    var mul = 1;

    while (byteLength > 0 && (mul *= 0x100)) {
      val += this[offset + --byteLength] * mul;
    }

    return val;
  };

  Buffer.prototype.readUInt8 = function readUInt8(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 1, this.length);
    return this[offset];
  };

  Buffer.prototype.readUInt16LE = function readUInt16LE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 2, this.length);
    return this[offset] | this[offset + 1] << 8;
  };

  Buffer.prototype.readUInt16BE = function readUInt16BE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 2, this.length);
    return this[offset] << 8 | this[offset + 1];
  };

  Buffer.prototype.readUInt32LE = function readUInt32LE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return (this[offset] | this[offset + 1] << 8 | this[offset + 2] << 16) + this[offset + 3] * 0x1000000;
  };

  Buffer.prototype.readUInt32BE = function readUInt32BE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return this[offset] * 0x1000000 + (this[offset + 1] << 16 | this[offset + 2] << 8 | this[offset + 3]);
  };

  Buffer.prototype.readIntLE = function readIntLE(offset, byteLength, noAssert) {
    offset = offset | 0;
    byteLength = byteLength | 0;
    if (!noAssert) checkOffset(offset, byteLength, this.length);
    var val = this[offset];
    var mul = 1;
    var i = 0;

    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul;
    }

    mul *= 0x80;
    if (val >= mul) val -= Math.pow(2, 8 * byteLength);
    return val;
  };

  Buffer.prototype.readIntBE = function readIntBE(offset, byteLength, noAssert) {
    offset = offset | 0;
    byteLength = byteLength | 0;
    if (!noAssert) checkOffset(offset, byteLength, this.length);
    var i = byteLength;
    var mul = 1;
    var val = this[offset + --i];

    while (i > 0 && (mul *= 0x100)) {
      val += this[offset + --i] * mul;
    }

    mul *= 0x80;
    if (val >= mul) val -= Math.pow(2, 8 * byteLength);
    return val;
  };

  Buffer.prototype.readInt8 = function readInt8(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 1, this.length);
    if (!(this[offset] & 0x80)) return this[offset];
    return (0xff - this[offset] + 1) * -1;
  };

  Buffer.prototype.readInt16LE = function readInt16LE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 2, this.length);
    var val = this[offset] | this[offset + 1] << 8;
    return val & 0x8000 ? val | 0xFFFF0000 : val;
  };

  Buffer.prototype.readInt16BE = function readInt16BE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 2, this.length);
    var val = this[offset + 1] | this[offset] << 8;
    return val & 0x8000 ? val | 0xFFFF0000 : val;
  };

  Buffer.prototype.readInt32LE = function readInt32LE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return this[offset] | this[offset + 1] << 8 | this[offset + 2] << 16 | this[offset + 3] << 24;
  };

  Buffer.prototype.readInt32BE = function readInt32BE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return this[offset] << 24 | this[offset + 1] << 16 | this[offset + 2] << 8 | this[offset + 3];
  };

  Buffer.prototype.readFloatLE = function readFloatLE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return read(this, offset, true, 23, 4);
  };

  Buffer.prototype.readFloatBE = function readFloatBE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 4, this.length);
    return read(this, offset, false, 23, 4);
  };

  Buffer.prototype.readDoubleLE = function readDoubleLE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 8, this.length);
    return read(this, offset, true, 52, 8);
  };

  Buffer.prototype.readDoubleBE = function readDoubleBE(offset, noAssert) {
    if (!noAssert) checkOffset(offset, 8, this.length);
    return read(this, offset, false, 52, 8);
  };

  function checkInt(buf, value, offset, ext, max, min) {
    if (!internalIsBuffer(buf)) throw new TypeError('"buffer" argument must be a Buffer instance');
    if (value > max || value < min) throw new RangeError('"value" argument is out of bounds');
    if (offset + ext > buf.length) throw new RangeError('Index out of range');
  }

  Buffer.prototype.writeUIntLE = function writeUIntLE(value, offset, byteLength, noAssert) {
    value = +value;
    offset = offset | 0;
    byteLength = byteLength | 0;

    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1;
      checkInt(this, value, offset, byteLength, maxBytes, 0);
    }

    var mul = 1;
    var i = 0;
    this[offset] = value & 0xFF;

    while (++i < byteLength && (mul *= 0x100)) {
      this[offset + i] = value / mul & 0xFF;
    }

    return offset + byteLength;
  };

  Buffer.prototype.writeUIntBE = function writeUIntBE(value, offset, byteLength, noAssert) {
    value = +value;
    offset = offset | 0;
    byteLength = byteLength | 0;

    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1;
      checkInt(this, value, offset, byteLength, maxBytes, 0);
    }

    var i = byteLength - 1;
    var mul = 1;
    this[offset + i] = value & 0xFF;

    while (--i >= 0 && (mul *= 0x100)) {
      this[offset + i] = value / mul & 0xFF;
    }

    return offset + byteLength;
  };

  Buffer.prototype.writeUInt8 = function writeUInt8(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0);
    if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value);
    this[offset] = value & 0xff;
    return offset + 1;
  };

  function objectWriteUInt16(buf, value, offset, littleEndian) {
    if (value < 0) value = 0xffff + value + 1;

    for (var i = 0, j = Math.min(buf.length - offset, 2); i < j; ++i) {
      buf[offset + i] = (value & 0xff << 8 * (littleEndian ? i : 1 - i)) >>> (littleEndian ? i : 1 - i) * 8;
    }
  }

  Buffer.prototype.writeUInt16LE = function writeUInt16LE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value & 0xff;
      this[offset + 1] = value >>> 8;
    } else {
      objectWriteUInt16(this, value, offset, true);
    }

    return offset + 2;
  };

  Buffer.prototype.writeUInt16BE = function writeUInt16BE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value >>> 8;
      this[offset + 1] = value & 0xff;
    } else {
      objectWriteUInt16(this, value, offset, false);
    }

    return offset + 2;
  };

  function objectWriteUInt32(buf, value, offset, littleEndian) {
    if (value < 0) value = 0xffffffff + value + 1;

    for (var i = 0, j = Math.min(buf.length - offset, 4); i < j; ++i) {
      buf[offset + i] = value >>> (littleEndian ? i : 3 - i) * 8 & 0xff;
    }
  }

  Buffer.prototype.writeUInt32LE = function writeUInt32LE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset + 3] = value >>> 24;
      this[offset + 2] = value >>> 16;
      this[offset + 1] = value >>> 8;
      this[offset] = value & 0xff;
    } else {
      objectWriteUInt32(this, value, offset, true);
    }

    return offset + 4;
  };

  Buffer.prototype.writeUInt32BE = function writeUInt32BE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value >>> 24;
      this[offset + 1] = value >>> 16;
      this[offset + 2] = value >>> 8;
      this[offset + 3] = value & 0xff;
    } else {
      objectWriteUInt32(this, value, offset, false);
    }

    return offset + 4;
  };

  Buffer.prototype.writeIntLE = function writeIntLE(value, offset, byteLength, noAssert) {
    value = +value;
    offset = offset | 0;

    if (!noAssert) {
      var limit = Math.pow(2, 8 * byteLength - 1);
      checkInt(this, value, offset, byteLength, limit - 1, -limit);
    }

    var i = 0;
    var mul = 1;
    var sub = 0;
    this[offset] = value & 0xFF;

    while (++i < byteLength && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i - 1] !== 0) {
        sub = 1;
      }

      this[offset + i] = (value / mul >> 0) - sub & 0xFF;
    }

    return offset + byteLength;
  };

  Buffer.prototype.writeIntBE = function writeIntBE(value, offset, byteLength, noAssert) {
    value = +value;
    offset = offset | 0;

    if (!noAssert) {
      var limit = Math.pow(2, 8 * byteLength - 1);
      checkInt(this, value, offset, byteLength, limit - 1, -limit);
    }

    var i = byteLength - 1;
    var mul = 1;
    var sub = 0;
    this[offset + i] = value & 0xFF;

    while (--i >= 0 && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i + 1] !== 0) {
        sub = 1;
      }

      this[offset + i] = (value / mul >> 0) - sub & 0xFF;
    }

    return offset + byteLength;
  };

  Buffer.prototype.writeInt8 = function writeInt8(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80);
    if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value);
    if (value < 0) value = 0xff + value + 1;
    this[offset] = value & 0xff;
    return offset + 1;
  };

  Buffer.prototype.writeInt16LE = function writeInt16LE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value & 0xff;
      this[offset + 1] = value >>> 8;
    } else {
      objectWriteUInt16(this, value, offset, true);
    }

    return offset + 2;
  };

  Buffer.prototype.writeInt16BE = function writeInt16BE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value >>> 8;
      this[offset + 1] = value & 0xff;
    } else {
      objectWriteUInt16(this, value, offset, false);
    }

    return offset + 2;
  };

  Buffer.prototype.writeInt32LE = function writeInt32LE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000);

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value & 0xff;
      this[offset + 1] = value >>> 8;
      this[offset + 2] = value >>> 16;
      this[offset + 3] = value >>> 24;
    } else {
      objectWriteUInt32(this, value, offset, true);
    }

    return offset + 4;
  };

  Buffer.prototype.writeInt32BE = function writeInt32BE(value, offset, noAssert) {
    value = +value;
    offset = offset | 0;
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000);
    if (value < 0) value = 0xffffffff + value + 1;

    if (Buffer.TYPED_ARRAY_SUPPORT) {
      this[offset] = value >>> 24;
      this[offset + 1] = value >>> 16;
      this[offset + 2] = value >>> 8;
      this[offset + 3] = value & 0xff;
    } else {
      objectWriteUInt32(this, value, offset, false);
    }

    return offset + 4;
  };

  function checkIEEE754(buf, value, offset, ext, max, min) {
    if (offset + ext > buf.length) throw new RangeError('Index out of range');
    if (offset < 0) throw new RangeError('Index out of range');
  }

  function writeFloat(buf, value, offset, littleEndian, noAssert) {
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 4);
    }

    write(buf, value, offset, littleEndian, 23, 4);
    return offset + 4;
  }

  Buffer.prototype.writeFloatLE = function writeFloatLE(value, offset, noAssert) {
    return writeFloat(this, value, offset, true, noAssert);
  };

  Buffer.prototype.writeFloatBE = function writeFloatBE(value, offset, noAssert) {
    return writeFloat(this, value, offset, false, noAssert);
  };

  function writeDouble(buf, value, offset, littleEndian, noAssert) {
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 8);
    }

    write(buf, value, offset, littleEndian, 52, 8);
    return offset + 8;
  }

  Buffer.prototype.writeDoubleLE = function writeDoubleLE(value, offset, noAssert) {
    return writeDouble(this, value, offset, true, noAssert);
  };

  Buffer.prototype.writeDoubleBE = function writeDoubleBE(value, offset, noAssert) {
    return writeDouble(this, value, offset, false, noAssert);
  }; // copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)


  Buffer.prototype.copy = function copy(target, targetStart, start, end) {
    if (!start) start = 0;
    if (!end && end !== 0) end = this.length;
    if (targetStart >= target.length) targetStart = target.length;
    if (!targetStart) targetStart = 0;
    if (end > 0 && end < start) end = start; // Copy 0 bytes; we're done

    if (end === start) return 0;
    if (target.length === 0 || this.length === 0) return 0; // Fatal error conditions

    if (targetStart < 0) {
      throw new RangeError('targetStart out of bounds');
    }

    if (start < 0 || start >= this.length) throw new RangeError('sourceStart out of bounds');
    if (end < 0) throw new RangeError('sourceEnd out of bounds'); // Are we oob?

    if (end > this.length) end = this.length;

    if (target.length - targetStart < end - start) {
      end = target.length - targetStart + start;
    }

    var len = end - start;
    var i;

    if (this === target && start < targetStart && targetStart < end) {
      // descending copy from end
      for (i = len - 1; i >= 0; --i) {
        target[i + targetStart] = this[i + start];
      }
    } else if (len < 1000 || !Buffer.TYPED_ARRAY_SUPPORT) {
      // ascending copy from start
      for (i = 0; i < len; ++i) {
        target[i + targetStart] = this[i + start];
      }
    } else {
      Uint8Array.prototype.set.call(target, this.subarray(start, start + len), targetStart);
    }

    return len;
  }; // Usage:
  //    buffer.fill(number[, offset[, end]])
  //    buffer.fill(buffer[, offset[, end]])
  //    buffer.fill(string[, offset[, end]][, encoding])


  Buffer.prototype.fill = function fill(val, start, end, encoding) {
    // Handle string cases:
    if (typeof val === 'string') {
      if (typeof start === 'string') {
        encoding = start;
        start = 0;
        end = this.length;
      } else if (typeof end === 'string') {
        encoding = end;
        end = this.length;
      }

      if (val.length === 1) {
        var code = val.charCodeAt(0);

        if (code < 256) {
          val = code;
        }
      }

      if (encoding !== undefined && typeof encoding !== 'string') {
        throw new TypeError('encoding must be a string');
      }

      if (typeof encoding === 'string' && !Buffer.isEncoding(encoding)) {
        throw new TypeError('Unknown encoding: ' + encoding);
      }
    } else if (typeof val === 'number') {
      val = val & 255;
    } // Invalid ranges are not set to a default, so can range check early.


    if (start < 0 || this.length < start || this.length < end) {
      throw new RangeError('Out of range index');
    }

    if (end <= start) {
      return this;
    }

    start = start >>> 0;
    end = end === undefined ? this.length : end >>> 0;
    if (!val) val = 0;
    var i;

    if (typeof val === 'number') {
      for (i = start; i < end; ++i) {
        this[i] = val;
      }
    } else {
      var bytes = internalIsBuffer(val) ? val : utf8ToBytes(new Buffer(val, encoding).toString());
      var len = bytes.length;

      for (i = 0; i < end - start; ++i) {
        this[i + start] = bytes[i % len];
      }
    }

    return this;
  }; // HELPER FUNCTIONS
  // ================


  var INVALID_BASE64_RE = /[^+\/0-9A-Za-z-_]/g;

  function base64clean(str) {
    // Node strips out invalid characters like \n and \t from the string, base64-js does not
    str = stringtrim(str).replace(INVALID_BASE64_RE, ''); // Node converts strings with length < 2 to ''

    if (str.length < 2) return ''; // Node allows for non-padded base64 strings (missing trailing ===), base64-js does not

    while (str.length % 4 !== 0) {
      str = str + '=';
    }

    return str;
  }

  function stringtrim(str) {
    if (str.trim) return str.trim();
    return str.replace(/^\s+|\s+$/g, '');
  }

  function toHex(n) {
    if (n < 16) return '0' + n.toString(16);
    return n.toString(16);
  }

  function utf8ToBytes(string, units) {
    units = units || Infinity;
    var codePoint;
    var length = string.length;
    var leadSurrogate = null;
    var bytes = [];

    for (var i = 0; i < length; ++i) {
      codePoint = string.charCodeAt(i); // is surrogate component

      if (codePoint > 0xD7FF && codePoint < 0xE000) {
        // last char was a lead
        if (!leadSurrogate) {
          // no lead yet
          if (codePoint > 0xDBFF) {
            // unexpected trail
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD);
            continue;
          } else if (i + 1 === length) {
            // unpaired lead
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD);
            continue;
          } // valid lead


          leadSurrogate = codePoint;
          continue;
        } // 2 leads in a row


        if (codePoint < 0xDC00) {
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD);
          leadSurrogate = codePoint;
          continue;
        } // valid surrogate pair


        codePoint = (leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00) + 0x10000;
      } else if (leadSurrogate) {
        // valid bmp char, but last char was a lead
        if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD);
      }

      leadSurrogate = null; // encode utf8

      if (codePoint < 0x80) {
        if ((units -= 1) < 0) break;
        bytes.push(codePoint);
      } else if (codePoint < 0x800) {
        if ((units -= 2) < 0) break;
        bytes.push(codePoint >> 0x6 | 0xC0, codePoint & 0x3F | 0x80);
      } else if (codePoint < 0x10000) {
        if ((units -= 3) < 0) break;
        bytes.push(codePoint >> 0xC | 0xE0, codePoint >> 0x6 & 0x3F | 0x80, codePoint & 0x3F | 0x80);
      } else if (codePoint < 0x110000) {
        if ((units -= 4) < 0) break;
        bytes.push(codePoint >> 0x12 | 0xF0, codePoint >> 0xC & 0x3F | 0x80, codePoint >> 0x6 & 0x3F | 0x80, codePoint & 0x3F | 0x80);
      } else {
        throw new Error('Invalid code point');
      }
    }

    return bytes;
  }

  function asciiToBytes(str) {
    var byteArray = [];

    for (var i = 0; i < str.length; ++i) {
      // Node's code seems to be doing this and not & 0x7F..
      byteArray.push(str.charCodeAt(i) & 0xFF);
    }

    return byteArray;
  }

  function utf16leToBytes(str, units) {
    var c, hi, lo;
    var byteArray = [];

    for (var i = 0; i < str.length; ++i) {
      if ((units -= 2) < 0) break;
      c = str.charCodeAt(i);
      hi = c >> 8;
      lo = c % 256;
      byteArray.push(lo);
      byteArray.push(hi);
    }

    return byteArray;
  }

  function base64ToBytes(str) {
    return toByteArray(base64clean(str));
  }

  function blitBuffer(src, dst, offset, length) {
    for (var i = 0; i < length; ++i) {
      if (i + offset >= dst.length || i >= src.length) break;
      dst[i + offset] = src[i];
    }

    return i;
  }

  function isnan(val) {
    return val !== val; // eslint-disable-line no-self-compare
  } // the following is from is-buffer, also by Feross Aboukhadijeh and with same lisence
  // The _isBuffer check is for Safari 5-7 support, because it's missing
  // Object.prototype.constructor. Remove this eventually


  function isBuffer(obj) {
    return obj != null && (!!obj._isBuffer || isFastBuffer(obj) || isSlowBuffer(obj));
  }

  function isFastBuffer(obj) {
    return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj);
  } // For Node v0.10 support. Remove this eventually.


  function isSlowBuffer(obj) {
    return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isFastBuffer(obj.slice(0, 0));
  }

  // POST https://{host}/oauth/token?grant_type=client_credentials&scope={scope}
  // Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
  function buildRequestForClientCredentialsFlow(options) {
    if (!options) throw new Error('Missing required options');
    if (!options.host) throw new Error('Missing required option (host)');
    if (!options.projectKey) throw new Error('Missing required option (projectKey)');
    if (!options.credentials) throw new Error('Missing required option (credentials)');
    var _options$credentials = options.credentials,
        clientId = _options$credentials.clientId,
        clientSecret = _options$credentials.clientSecret;
    if (!(clientId && clientSecret)) throw new Error('Missing required credentials (clientId, clientSecret)');
    var scope = options.scopes ? options.scopes.join(' ') : undefined;
    var basicAuth = Buffer.from("".concat(clientId, ":").concat(clientSecret)).toString('base64'); // This is mostly useful for internal testing purposes to be able to check
    // other oauth endpoints.

    var oauthUri = options.oauthUri || '/oauth/token';
    var url = options.host.replace(/\/$/, '') + oauthUri;
    var body = "grant_type=client_credentials".concat(scope ? "&scope=".concat(scope) : '');
    return {
      basicAuth: basicAuth,
      url: url,
      body: body
    };
  }
  function buildRequestForPasswordFlow(options) {
    if (!options) throw new Error('Missing required options');
    if (!options.host) throw new Error('Missing required option (host)');
    if (!options.projectKey) throw new Error('Missing required option (projectKey)');
    if (!options.credentials) throw new Error('Missing required option (credentials)');
    var _options$credentials2 = options.credentials,
        clientId = _options$credentials2.clientId,
        clientSecret = _options$credentials2.clientSecret,
        user = _options$credentials2.user;
    var pKey = options.projectKey;
    if (!(clientId && clientSecret && user)) throw new Error('Missing required credentials (clientId, clientSecret, user)');
    var username = user.username,
        password = user.password;
    if (!(username && password)) throw new Error('Missing required user credentials (username, password)');
    var scope = (options.scopes || []).join(' ');
    var scopeStr = scope ? "&scope=".concat(scope) : '';
    var basicAuth = Buffer.from("".concat(clientId, ":").concat(clientSecret)).toString('base64'); // This is mostly useful for internal testing purposes to be able to check
    // other oauth endpoints.

    var oauthUri = options.oauthUri || "/oauth/".concat(pKey, "/customers/token");
    var url = options.host.replace(/\/$/, '') + oauthUri; // eslint-disable-next-line max-len
    // encode username and password as requested by platform

    var body = "grant_type=password&username=".concat(encodeURIComponent(username), "&password=").concat(encodeURIComponent(password)).concat(scopeStr);
    return {
      basicAuth: basicAuth,
      url: url,
      body: body
    };
  }
  function buildRequestForRefreshTokenFlow(options) {
    if (!options) throw new Error('Missing required options');
    if (!options.host) throw new Error('Missing required option (host)');
    if (!options.projectKey) throw new Error('Missing required option (projectKey)');
    if (!options.credentials) throw new Error('Missing required option (credentials)');
    if (!options.refreshToken) throw new Error('Missing required option (refreshToken)');
    var _options$credentials3 = options.credentials,
        clientId = _options$credentials3.clientId,
        clientSecret = _options$credentials3.clientSecret;
    if (!(clientId && clientSecret)) throw new Error('Missing required credentials (clientId, clientSecret)');
    var basicAuth = Buffer.from("".concat(clientId, ":").concat(clientSecret)).toString('base64'); // This is mostly useful for internal testing purposes to be able to check
    // other oauth endpoints.

    var oauthUri = options.oauthUri || '/oauth/token';
    var url = options.host.replace(/\/$/, '') + oauthUri;
    var body = "grant_type=refresh_token&refresh_token=".concat(encodeURIComponent(options.refreshToken));
    return {
      basicAuth: basicAuth,
      url: url,
      body: body
    };
  }
  function buildRequestForAnonymousSessionFlow(options) {
    if (!options) throw new Error('Missing required options');
    if (!options.projectKey) throw new Error('Missing required option (projectKey)');
    var pKey = options.projectKey; // eslint-disable-next-line no-param-reassign

    options.oauthUri = options.oauthUri || "/oauth/".concat(pKey, "/anonymous/token");
    var result = buildRequestForClientCredentialsFlow(options);
    if (options.credentials.anonymousId) result.body += "&anonymous_id=".concat(options.credentials.anonymousId);
    return _objectSpread2({}, result);
  }

  function buildTokenCacheKey(options) {
    return {
      clientId: options.credentials.clientId,
      host: options.host,
      projectKey: options.projectKey
    };
  }

  function mergeAuthHeader(token, req) {
    return _objectSpread2({}, req, {
      headers: _objectSpread2({}, req.headers, {
        Authorization: "Bearer ".concat(token)
      })
    });
  }

  function calculateExpirationTime(expiresIn) {
    return Date.now() + expiresIn * 1000 - // Add a gap of 2 hours before expiration time.
    2 * 60 * 60 * 1000;
  }

  function executeRequest(_ref) {
    var fetcher = _ref.fetcher,
        url = _ref.url,
        basicAuth = _ref.basicAuth,
        body = _ref.body,
        tokenCache = _ref.tokenCache,
        requestState = _ref.requestState,
        pendingTasks = _ref.pendingTasks,
        response = _ref.response,
        tokenCacheKey = _ref.tokenCacheKey;
    fetcher(url, {
      method: 'POST',
      headers: {
        Authorization: "Basic ".concat(basicAuth),
        'Content-Length': Buffer.byteLength(body).toString(),
        'Content-Type': 'application/x-www-form-urlencoded'
      },
      body: body
    }).then(function (res) {
      if (res.ok) return res.json().then(function (_ref2) {
        var token = _ref2.access_token,
            expiresIn = _ref2.expires_in,
            refreshToken = _ref2.refresh_token;
        var expirationTime = calculateExpirationTime(expiresIn); // Cache new token

        tokenCache.set({
          token: token,
          expirationTime: expirationTime,
          refreshToken: refreshToken
        }, tokenCacheKey); // Dispatch all pending requests

        requestState.set(false); // Freeze and copy pending queue, reset original one for accepting
        // new pending tasks

        var executionQueue = pendingTasks.slice(); // eslint-disable-next-line no-param-reassign

        pendingTasks = [];
        executionQueue.forEach(function (task) {
          // Assign the new token in the request header
          var requestWithAuth = mergeAuthHeader(token, task.request); // console.log('test', cache, pendingTasks)
          // Continue by calling the task's own next function

          task.next(requestWithAuth, task.response);
        });
      }); // Handle error response

      return res.text().then(function (text) {
        var parsed;

        try {
          parsed = JSON.parse(text);
        } catch (error) {
          /* noop */
        }

        var error = new Error(parsed ? parsed.message : text);
        if (parsed) error.body = parsed;
        response.reject(error);
      });
    }).catch(function (error) {
      if (response && typeof response.reject === 'function') response.reject(error);
    });
  }

  function authMiddlewareBase(_ref3, next, userOptions) {
    var request = _ref3.request,
        response = _ref3.response,
        url = _ref3.url,
        basicAuth = _ref3.basicAuth,
        body = _ref3.body,
        pendingTasks = _ref3.pendingTasks,
        requestState = _ref3.requestState,
        tokenCache = _ref3.tokenCache,
        tokenCacheKey = _ref3.tokenCacheKey,
        fetcher = _ref3.fetch;
    if (!fetcher && typeof fetch === 'undefined') throw new Error('`fetch` is not available. Please pass in `fetch` as an option or have it globally available.');
    if (!fetcher) // eslint-disable-next-line
      fetcher = fetch; // Check if there is already a `Authorization` header in the request.
    // If so, then go directly to the next middleware.

    if (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) {
      next(request, response);
      return;
    } // If there was a token in the tokenCache, and it's not expired, append
    // the token in the `Authorization` header.


    var tokenObj = tokenCache.get(tokenCacheKey);

    if (tokenObj && tokenObj.token && Date.now() < tokenObj.expirationTime) {
      var requestWithAuth = mergeAuthHeader(tokenObj.token, request);
      next(requestWithAuth, response);
      return;
    } // Keep pending tasks until a token is fetched
    // Save next function as well, to call it once the token has been fetched, which prevents
    // unexpected behaviour in a context in which the next function uses global vars
    // or Promises to capture the token to hand it to other libraries, e.g. Apollo


    pendingTasks.push({
      request: request,
      response: response,
      next: next
    }); // If a token is currently being fetched, just wait ;)

    if (requestState.get()) return; // Mark that a token is being fetched

    requestState.set(true); // If there was a refreshToken in the tokenCache, and there was an expired
    // token or no token in the tokenCache, use the refreshToken flow

    if (tokenObj && tokenObj.refreshToken && (!tokenObj.token || tokenObj.token && Date.now() > tokenObj.expirationTime)) {
      if (!userOptions) throw new Error('Missing required options') // eslint-disable-next-line
      ;
      executeRequest(_objectSpread2({
        fetcher: fetcher
      }, buildRequestForRefreshTokenFlow(_objectSpread2({}, userOptions, {
        refreshToken: tokenObj.refreshToken
      })), {
        tokenCacheKey: tokenCacheKey,
        tokenCache: tokenCache,
        requestState: requestState,
        pendingTasks: pendingTasks,
        response: response
      }));
      return;
    } // Token and refreshToken are not present or invalid. Request a new token...


    executeRequest({
      fetcher: fetcher,
      url: url,
      basicAuth: basicAuth,
      body: body,
      tokenCacheKey: tokenCacheKey,
      tokenCache: tokenCache,
      requestState: requestState,
      pendingTasks: pendingTasks,
      response: response
    });
  }

  function store(initVal) {
    var value = initVal;
    return {
      get: function get() {
        return value;
      },
      set: function set(val) {
        value = val;
        return value;
      }
    };
  }

  function createAuthMiddlewareForClientCredentialsFlow(options) {
    var tokenCache = options.tokenCache || store({
      token: '',
      expirationTime: -1
    });
    var requestState = store(false);
    var pendingTasks = [];
    return function (next) {
      return function (request, response) {
        // Check if there is already a `Authorization` header in the request.
        // If so, then go directly to the next middleware.
        if (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) {
          next(request, response);
          return;
        }

        var params = _objectSpread2({
          request: request,
          response: response
        }, buildRequestForClientCredentialsFlow(options), {
          pendingTasks: pendingTasks,
          requestState: requestState,
          tokenCache: tokenCache,
          tokenCacheKey: buildTokenCacheKey(options),
          fetch: options.fetch
        });

        authMiddlewareBase(params, next);
      };
    };
  }

  function createAuthMiddlewareForPasswordFlow(options) {
    var tokenCache = store({});
    var pendingTasks = [];
    var requestState = store(false);
    return function (next) {
      return function (request, response) {
        // Check if there is already a `Authorization` header in the request.
        // If so, then go directly to the next middleware.
        if (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) {
          next(request, response);
          return;
        }

        var params = _objectSpread2({
          request: request,
          response: response
        }, buildRequestForPasswordFlow(options), {
          pendingTasks: pendingTasks,
          requestState: requestState,
          tokenCache: tokenCache,
          fetch: options.fetch
        });

        authMiddlewareBase(params, next, options);
      };
    };
  }

  function createAuthMiddlewareForRefreshTokenFlow(options) {
    var tokenCache = store({});
    var pendingTasks = [];
    var requestState = store(false);
    return function (next) {
      return function (request, response) {
        // Check if there is already a `Authorization` header in the request.
        // If so, then go directly to the next middleware.
        if (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) {
          next(request, response);
          return;
        }

        var params = _objectSpread2({
          request: request,
          response: response
        }, buildRequestForRefreshTokenFlow(options), {
          pendingTasks: pendingTasks,
          requestState: requestState,
          tokenCache: tokenCache,
          fetch: options.fetch
        });

        authMiddlewareBase(params, next);
      };
    };
  }

  function createAuthMiddlewareForAnonymousSessionFlow(options) {
    var tokenCache = store({});
    var pendingTasks = [];
    var requestState = store(false);
    return function (next) {
      return function (request, response) {
        // Check if there is already a `Authorization` header in the request.
        // If so, then go directly to the next middleware.
        if (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) {
          next(request, response);
          return;
        }

        var params = _objectSpread2({
          request: request,
          response: response
        }, buildRequestForAnonymousSessionFlow(options), {
          pendingTasks: pendingTasks,
          requestState: requestState,
          tokenCache: tokenCache,
          fetch: options.fetch
        });

        authMiddlewareBase(params, next, options);
      };
    };
  }

  function createAuthMiddlewareWithExistingToken() {
    var authorization = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : '';
    var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
    return function (next) {
      return function (request, response) {
        if (typeof authorization !== 'string') throw new Error('authorization must be a string');
        var force = options.force === undefined ? true : options.force;
        /** The request will not be modified if:
         *  1. no argument is passed
         *  2. force is false and authorization header exists
         */

        if (!authorization || (request.headers && request.headers.authorization || request.headers && request.headers.Authorization) && force === false) {
          return next(request, response);
        }

        var requestWithAuth = _objectSpread2({}, request, {
          headers: _objectSpread2({}, request.headers, {
            Authorization: authorization
          })
        });

        return next(requestWithAuth, response);
      };
    };
  }

  var MANAGE_PROJECT = 'manage_project';
  var MANAGE_PRODUCTS = 'manage_products';
  var VIEW_PRODUCTS = 'view_products';
  var MANAGE_ORDERS = 'manage_orders';
  var VIEW_ORDERS = 'view_orders';
  var MANAGE_MY_ORDERS = 'manage_my_orders';
  var MANAGE_CUSTOMERS = 'manage_customers';
  var VIEW_CUSTOMERS = 'view_customers';
  var MANAGE_MY_PROFILE = 'manage_my_profile';
  var MANAGE_TYPES = 'manage_types';
  var VIEW_TYPES = 'view_types';
  var MANAGE_PAYMENTS = 'manage_payments';
  var VIEW_PAYMENTS = 'view_payments';
  var CREATE_ANONYMOUS_TOKEN = 'create_anonymous_token';
  var MANAGE_SUBSCRIPTIONS = 'manage_subscriptions';

  var scopes = /*#__PURE__*/Object.freeze({
    __proto__: null,
    MANAGE_PROJECT: MANAGE_PROJECT,
    MANAGE_PRODUCTS: MANAGE_PRODUCTS,
    VIEW_PRODUCTS: VIEW_PRODUCTS,
    MANAGE_ORDERS: MANAGE_ORDERS,
    VIEW_ORDERS: VIEW_ORDERS,
    MANAGE_MY_ORDERS: MANAGE_MY_ORDERS,
    MANAGE_CUSTOMERS: MANAGE_CUSTOMERS,
    VIEW_CUSTOMERS: VIEW_CUSTOMERS,
    MANAGE_MY_PROFILE: MANAGE_MY_PROFILE,
    MANAGE_TYPES: MANAGE_TYPES,
    VIEW_TYPES: VIEW_TYPES,
    MANAGE_PAYMENTS: MANAGE_PAYMENTS,
    VIEW_PAYMENTS: VIEW_PAYMENTS,
    CREATE_ANONYMOUS_TOKEN: CREATE_ANONYMOUS_TOKEN,
    MANAGE_SUBSCRIPTIONS: MANAGE_SUBSCRIPTIONS
  });

  exports.createAuthMiddlewareForAnonymousSessionFlow = createAuthMiddlewareForAnonymousSessionFlow;
  exports.createAuthMiddlewareForClientCredentialsFlow = createAuthMiddlewareForClientCredentialsFlow;
  exports.createAuthMiddlewareForPasswordFlow = createAuthMiddlewareForPasswordFlow;
  exports.createAuthMiddlewareForRefreshTokenFlow = createAuthMiddlewareForRefreshTokenFlow;
  exports.createAuthMiddlewareWithExistingToken = createAuthMiddlewareWithExistingToken;
  exports.scopes = scopes;

  Object.defineProperty(exports, '__esModule', { value: true });

})));