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'use strict';
var toStringTagSymbol = require('es6-symbol').toStringTag
, toString = Object.prototype.toString
, id = '[object WeakMap]'
, Global = (typeof WeakMap === 'undefined') ? null : WeakMap;
module.exports = function (x) {
return (x && ((Global && (x instanceof Global)) ||
(toString.call(x) === id) || (x[toStringTagSymbol] === 'WeakMap'))) ||
false;
};