def METHOD_NAME(doc_id):
    """Look up a document ID
    :param doc_id: ID of document to look for
    :returns: LookupResult or None
    """
    if doc_id is None:
        raise TypeError('`doc_id` is NoneType, expected str.')
    result, _ = lookup_id_in_databases(doc_id, get_databases().values())
    return result