code: function(control) {
  
        var i;
        for (i = 0; i < this._events.length; i++) {
           var evt = this._events[i];
  
           if (evt.eventType === "ChildWorkflowExecutionCompleted") {
  
              var initiatedEventId = evt.childWorkflowExecutionCompletedEventAttributes.initiatedEventId;
              var initiatedEvent = this.eventById(initiatedEventId);
  
              if (initiatedEvent.startChildWorkflowExecutionInitiatedEventAttributes.control === control) {
  
                 var result = evt.childWorkflowExecutionCompletedEventAttributes.result;
  
                 try {
                    result = JSON.parse(result);
                 }
                 catch(ex) {}
  
                 return result;
              }
           }
        }
  
        return null;
     }
docs: Get the results of a completed child workflow
  @param {String} control
  @returns {Mixed}