public Builder setExecuteStepRequest(main.Messages.ExecuteStepRequest value) {
        if (executeStepRequestBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          executeStepRequest_ = value;
          onChanged();
        } else {
          executeStepRequestBuilder_.setMessage(value);
        }
        bitField0_ |= 0x00000080;
        return this;
      }