public Builder mergeHdfsDataSource(
          com.google.storagetransfer.v1.proto.TransferTypes.HdfsData value) {
        if (hdfsDataSourceBuilder_ == null) {
          if (dataSourceCase_ == 20
              && dataSource_
                  != com.google.storagetransfer.v1.proto.TransferTypes.HdfsData
                      .getDefaultInstance()) {
            dataSource_ =
                com.google.storagetransfer.v1.proto.TransferTypes.HdfsData.newBuilder(
                        (com.google.storagetransfer.v1.proto.TransferTypes.HdfsData) dataSource_)
                    .mergeFrom(value)
                    .buildPartial();
          } else {
            dataSource_ = value;
          }
          onChanged();
        } else {
          if (dataSourceCase_ == 20) {
            hdfsDataSourceBuilder_.mergeFrom(value);
          } else {
            hdfsDataSourceBuilder_.setMessage(value);
          }
        }
        dataSourceCase_ = 20;
        return this;
      }
<pre>
An HDFS cluster data source.
</pre>

<code>.google.storagetransfer.v1.HdfsData hdfs_data_source = 20;</code>
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java