@java.lang.Override
    public boolean hasGcsDataSource() {
      return dataSourceCase_ == 1;
    }
<pre>
The Cloud Storage bucket from which to replicate objects.
</pre>

<code>.google.storagetransfer.v1.GcsData gcs_data_source = 1;</code>

@return Whether the gcsDataSource field is set.
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java