'use strict'; var getBuiltIn = require('../internals/get-built-in'); var uncurryThis = require('../internals/function-uncurry-this'); var Symbol = getBuiltIn('Symbol'); var keyFor = Symbol.keyFor; var thisSymbolValue = uncurryThis(Symbol.prototype.valueOf); // `Symbol.isRegisteredSymbol` method // https://tc39.es/proposal-symbol-predicates/#sec-symbol-isregisteredsymbol module.exports = Symbol.isRegisteredSymbol || function isRegisteredSymbol(value) { try { return keyFor(thisSymbolValue(value)) !== undefined; } catch (error) { return false; } };