| 'use strict'; | 
| // https://github.com/tc39/proposal-explicit-resource-management | 
| var call = require('../internals/function-call'); | 
| var defineBuiltIn = require('../internals/define-built-in'); | 
| var getMethod = require('../internals/get-method'); | 
| var hasOwn = require('../internals/has-own-property'); | 
| var wellKnownSymbol = require('../internals/well-known-symbol'); | 
| var IteratorPrototype = require('../internals/iterators-core').IteratorPrototype; | 
|   | 
| var DISPOSE = wellKnownSymbol('dispose'); | 
|   | 
| if (!hasOwn(IteratorPrototype, DISPOSE)) { | 
|   defineBuiltIn(IteratorPrototype, DISPOSE, function () { | 
|     var $return = getMethod(this, 'return'); | 
|     if ($return) call($return, this); | 
|   }); | 
| } |