@Override
  public Exporter<?, ?> getExporter(DataVertical transferDataType) {
    Preconditions.checkArgument(
        initialized, "Trying to call getExporter before initalizing TwitterTransferExtension");
    Preconditions.checkArgument(
        SUPPORTED_TYPES.contains(transferDataType),
        "Export of " + transferDataType + " not supported by Twitter");
    return exporter;
  }
Extension to allow Twitter content to be transferred.

<p>Currently only photos content to be exported/imported.

<p>In the future if a social vertical gets defined support should be added for that.
extensions/data-transfer/portability-data-transfer-twitter/src/main/java/org/datatransferproject/transfer/twitter/TwitterTransferExtension.java