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- 'use strict';
- module.exports = function () {
- var symbol;
- if (typeof Symbol !== 'function') return false;
- symbol = Symbol('test symbol');
- try { String(symbol); } catch (e) { return false; }
- if (typeof Symbol.iterator === 'symbol') return true;
- // Return 'true' for polyfills
- if (typeof Symbol.isConcatSpreadable !== 'object') return false;
- if (typeof Symbol.iterator !== 'object') return false;
- if (typeof Symbol.toPrimitive !== 'object') return false;
- if (typeof Symbol.toStringTag !== 'object') return false;
- if (typeof Symbol.unscopables !== 'object') return false;
- return true;
- };
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