def parse_document_id(chrom, pos, ref, alt, variant_type, case_id):
return generate_md5_key([chrom, pos, ref, alt, variant_type, case_id])<EOL>
Parse the unique document id for a variant.

    This will always be unique in the database.

    Args:
        chrom(str)
        pos(str)
        ref(str)
        alt(str)
        variant_type(str): 'clinical' or 'research'
        case_id(str): unqiue family id

    Returns:
        document_id(str): The unique document id in an md5 string