private com.google.protobuf.SingleFieldBuilder<
          main.Messages.SpecExecutionStartingRequest, main.Messages.SpecExecutionStartingRequest.Builder, main.Messages.SpecExecutionStartingRequestOrBuilder> 
          getSpecExecutionStartingRequestFieldBuilder() {
        if (specExecutionStartingRequestBuilder_ == null) {
          specExecutionStartingRequestBuilder_ = new com.google.protobuf.SingleFieldBuilder<
              main.Messages.SpecExecutionStartingRequest, main.Messages.SpecExecutionStartingRequest.Builder, main.Messages.SpecExecutionStartingRequestOrBuilder>(
                  specExecutionStartingRequest_,
                  getParentForChildren(),
                  isClean());
          specExecutionStartingRequest_ = null;
        }
        return specExecutionStartingRequestBuilder_;
      }