private com.google.protobuf.SingleFieldBuilderV3<
              com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData,
              com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData.Builder,
              com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageDataOrBuilder>
          getAzureBlobStorageDataSourceFieldBuilder() {
        if (azureBlobStorageDataSourceBuilder_ == null) {
          if (!(dataSourceCase_ == 8)) {
            dataSource_ =
                com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData
                    .getDefaultInstance();
          }
          azureBlobStorageDataSourceBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData,
                  com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData.Builder,
                  com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageDataOrBuilder>(
                  (com.google.storagetransfer.v1.proto.TransferTypes.AzureBlobStorageData)
                      dataSource_,
                  getParentForChildren(),
                  isClean());
          dataSource_ = null;
        }
        dataSourceCase_ = 8;
        onChanged();
        return azureBlobStorageDataSourceBuilder_;
      }
<pre>
An Azure Blob Storage data source.
</pre>

<code>.google.storagetransfer.v1.AzureBlobStorageData azure_blob_storage_data_source = 8;
</code>
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java