code: public synchronized RequestResult getLastResult() {
          if (this.requestResults == null || this.requestResults.size() == 0) {
              return null;
          }
          else {
              return this.requestResults.get(this.requestResults.size() - 1);
          }
      }
docs: Gets the last request result encountered for the operation.
  
  @return A {@link RequestResult} object which represents the last request result.