public Builder clearScenarioExecutionStartingRequest() {
        if (scenarioExecutionStartingRequestBuilder_ == null) {
          scenarioExecutionStartingRequest_ = main.Messages.ScenarioExecutionStartingRequest.getDefaultInstance();
          onChanged();
        } else {
          scenarioExecutionStartingRequestBuilder_.clear();
        }
        bitField0_ = (bitField0_ & ~0x00000020);
        return this;
      }