| 'use strict'; | 
| var aSet = require('../internals/a-set'); | 
| var add = require('../internals/set-helpers').add; | 
| var clone = require('../internals/set-clone'); | 
| var getSetRecord = require('../internals/get-set-record'); | 
| var iterateSimple = require('../internals/iterate-simple'); | 
|   | 
| // `Set.prototype.union` method | 
| // https://github.com/tc39/proposal-set-methods | 
| module.exports = function union(other) { | 
|   var O = aSet(this); | 
|   var keysIter = getSetRecord(other).getIterator(); | 
|   var result = clone(O); | 
|   iterateSimple(keysIter, function (it) { | 
|     add(result, it); | 
|   }); | 
|   return result; | 
| }; |