core-js/modules/esnext.map.merge.js

'use strict';
var $ = require('../internals/export');
var IS_PURE = require('../internals/is-pure');
var anObject = require('../internals/an-object');
var aFunction = require('../internals/a-function');
var iterate = require('../internals/iterate');

// `Map.prototype.merge` method
// https://github.com/tc39/proposal-collection-methods
$({ target: 'Map', proto: true, real: true, forced: IS_PURE }, {
  // eslint-disable-next-line no-unused-vars
  merge: function merge(iterable /* ...iterbles */) {
    var map = anObject(this);
    var setter = aFunction(map.set);
    var i = 0;
    while (i < arguments.length) {
      iterate(arguments[i++], setter, map, true);
    }
    return map;
  }
});