@Override
  public ImportResult importItem(
      UUID jobId,
      IdempotentImportExecutor idempotentExecutor,
      AD authData,
      ExportingType data
  ) throws Exception {
    return standinImporter.importItem(jobId, idempotentExecutor, authData, modelConverter.apply(data));
  }
@param standinImporter  existing importer
@param modelConverter function converting between some existing
   exporters' type to our stand-in importers' container types.
portability-spi-transfer/src/main/java/org/datatransferproject/spi/transfer/provider/converter/AnyToAnyImporter.java