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'use strict';
var $ = require('../internals/export');
var call = require('../internals/function-call');
var iterate = require('../internals/iterate');
var aCallable = require('../internals/a-callable');
// `Map.keyBy` method
// https://github.com/tc39/proposal-collection-methods
$({ target: 'Map', stat: true, forced: true }, {
keyBy: function keyBy(iterable, keyDerivative) {
var newMap = new this();
aCallable(keyDerivative);
var setter = aCallable(newMap.set);
iterate(iterable, function (element) {
call(setter, newMap, keyDerivative(element), element);
});
return newMap;
}
});