| 'use strict'; | 
| var wellKnownSymbol = require('../internals/well-known-symbol'); | 
| var defineProperty = require('../internals/object-define-property').f; | 
|   | 
| var METADATA = wellKnownSymbol('metadata'); | 
| var FunctionPrototype = Function.prototype; | 
|   | 
| // Function.prototype[@@metadata] | 
| // https://github.com/tc39/proposal-decorator-metadata | 
| if (FunctionPrototype[METADATA] === undefined) { | 
|   defineProperty(FunctionPrototype, METADATA, { | 
|     value: null | 
|   }); | 
| } |