1 | var global = require('../internals/global');
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2 | var shared = require('../internals/shared-store');
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3 | var getPrototypeOf = require('../internals/object-get-prototype-of');
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4 | var has = require('../internals/has');
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5 | var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
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6 | var wellKnownSymbol = require('../internals/well-known-symbol');
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7 | var IS_PURE = require('../internals/is-pure');
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8 |
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9 | var USE_FUNCTION_CONSTRUCTOR = 'USE_FUNCTION_CONSTRUCTOR';
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10 | var ASYNC_ITERATOR = wellKnownSymbol('asyncIterator');
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11 | var AsyncIterator = global.AsyncIterator;
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12 | var PassedAsyncIteratorPrototype = shared.AsyncIteratorPrototype;
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13 | var AsyncIteratorPrototype, prototype;
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14 |
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15 | if (!IS_PURE) {
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16 | if (PassedAsyncIteratorPrototype) {
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17 | AsyncIteratorPrototype = PassedAsyncIteratorPrototype;
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18 | } else if (typeof AsyncIterator == 'function') {
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19 | AsyncIteratorPrototype = AsyncIterator.prototype;
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20 | } else if (shared[USE_FUNCTION_CONSTRUCTOR] || global[USE_FUNCTION_CONSTRUCTOR]) {
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21 | try {
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22 |
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23 | prototype = getPrototypeOf(getPrototypeOf(getPrototypeOf(Function('return async function*(){}()')())));
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24 | if (getPrototypeOf(prototype) === Object.prototype) AsyncIteratorPrototype = prototype;
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25 | } catch (error) { }
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26 | }
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27 | }
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28 |
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29 | if (!AsyncIteratorPrototype) AsyncIteratorPrototype = {};
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30 |
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31 | if (!has(AsyncIteratorPrototype, ASYNC_ITERATOR)) {
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32 | createNonEnumerableProperty(AsyncIteratorPrototype, ASYNC_ITERATOR, function () {
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33 | return this;
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34 | });
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35 | }
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36 |
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37 | module.exports = AsyncIteratorPrototype;
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