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'use strict';
module.exports = function () {
var weakMap, x;
if (typeof WeakMap !== 'function') return false;
try {
// WebKit doesn't support arguments and crashes
weakMap = new WeakMap([[x = {}, 'one'], [{}, 'two'], [{}, 'three']]);
} catch (e) {
return false;
}
if (String(weakMap) !== '[object WeakMap]') return false;
if (typeof weakMap.set !== 'function') return false;
if (weakMap.set({}, 1) !== weakMap) return false;
if (typeof weakMap.delete !== 'function') return false;
if (typeof weakMap.has !== 'function') return false;
if (weakMap.get(x) !== 'one') return false;
return true;
};