| 'use strict'; | 
| // https://github.com/tc39/proposal-async-explicit-resource-management | 
| var call = require('../internals/function-call'); | 
| var defineBuiltIn = require('../internals/define-built-in'); | 
| var getBuiltIn = require('../internals/get-built-in'); | 
| var getMethod = require('../internals/get-method'); | 
| var hasOwn = require('../internals/has-own-property'); | 
| var wellKnownSymbol = require('../internals/well-known-symbol'); | 
| var AsyncIteratorPrototype = require('../internals/async-iterator-prototype'); | 
|   | 
| var ASYNC_DISPOSE = wellKnownSymbol('asyncDispose'); | 
| var Promise = getBuiltIn('Promise'); | 
|   | 
| if (!hasOwn(AsyncIteratorPrototype, ASYNC_DISPOSE)) { | 
|   defineBuiltIn(AsyncIteratorPrototype, ASYNC_DISPOSE, function () { | 
|     var O = this; | 
|     return new Promise(function (resolve, reject) { | 
|       var $return = getMethod(O, 'return'); | 
|       if ($return) { | 
|         Promise.resolve(call($return, O)).then(function () { | 
|           resolve(undefined); | 
|         }, reject); | 
|       } else resolve(undefined); | 
|     }); | 
|   }); | 
| } |