public Builder mergeStepValidateRequest(main.Messages.StepValidateRequest value) {
        if (stepValidateRequestBuilder_ == null) {
          if (((bitField0_ & 0x00000400) == 0x00000400) &&
              stepValidateRequest_ != main.Messages.StepValidateRequest.getDefaultInstance()) {
            stepValidateRequest_ =
              main.Messages.StepValidateRequest.newBuilder(stepValidateRequest_).mergeFrom(value).buildPartial();
          } else {
            stepValidateRequest_ = value;
          }
          onChanged();
        } else {
          stepValidateRequestBuilder_.mergeFrom(value);
        }
        bitField0_ |= 0x00000400;
        return this;
      }