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huazhiyu/node_modules/core-js/internals/symbol-constructor-detectio...

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'use strict';
/* eslint-disable es/no-symbol -- required for testing */
var V8_VERSION = require('../internals/engine-v8-version');
var fails = require('../internals/fails');
var global = require('../internals/global');
var $String = global.String;
// eslint-disable-next-line es/no-object-getownpropertysymbols -- required for testing
module.exports = !!Object.getOwnPropertySymbols && !fails(function () {
var symbol = Symbol('symbol detection');
// Chrome 38 Symbol has incorrect toString conversion
// `get-own-property-symbols` polyfill symbols converted to object are not Symbol instances
// nb: Do not call `String` directly to avoid this being optimized out to `symbol+''` which will,
// of course, fail.
return !$String(symbol) || !(Object(symbol) instanceof Symbol) ||
// Chrome 38-40 symbols are not inherited from DOM collections prototypes to instances
!Symbol.sham && V8_VERSION && V8_VERSION < 41;
});