def METHOD_NAME(configured_catalog: ConfiguredAirbyteCatalog) -> Mapping[str, List[CatalogField]]:
    """Get PK fields for each stream
    :param configured_catalog:
    :return:
    """
    data = {}
    for stream in configured_catalog.streams:
        helper = JsonSchemaHelper(schema=stream.stream.json_schema)
        pks = stream.primary_key or []
        data[stream.stream.name] = [helper.field(pk) for pk in pks]
    return data