code: Future<T> complete(Try<T> result) {
          // save the result
          this.response = Some(result);
  
          // notify all potential handlers
          notifyHandlers();
          return this;
      }
docs: Completes this Future with a result. <br>
  Invoked by the Promise owning this instance.
  
  @param result The result to complete with
  @return Returns itself