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'use strict'; var isObject = require('../internals/is-object'); var definePropertyModule = require('../internals/object-define-property'); var getPrototypeOf = require('../internals/object-get-prototype-of'); var wellKnownSymbol = require('../internals/well-known-symbol');
var HAS_INSTANCE = wellKnownSymbol('hasInstance'); var FunctionPrototype = Function.prototype;
// `Function.prototype[@@hasInstance]` method
// https://tc39.es/ecma262/#sec-function.prototype-@@hasinstance
if (!(HAS_INSTANCE in FunctionPrototype)) { definePropertyModule.f(FunctionPrototype, HAS_INSTANCE, { value: function (O) { if (typeof this != 'function' || !isObject(O)) return false; if (!isObject(this.prototype)) return O instanceof this; // for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this:
while (O = getPrototypeOf(O)) if (this.prototype === O) return true; return false; } }); }
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