code: public com.google.protobuf.ByteString
        getFilenameTensorNameBytes() {
      java.lang.Object ref = filenameTensorName_;
      if (ref instanceof java.lang.String) {
        com.google.protobuf.ByteString b = 
            com.google.protobuf.ByteString.copyFromUtf8(
                (java.lang.String) ref);
        filenameTensorName_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
docs: <pre>
  The name of the tensor in which to specify the filename when saving or
  restoring a model checkpoint.
  </pre>
  
  <code>optional string filename_tensor_name = 1;</code>