presto-redis/src/main/java/io/prestosql/plugin/redis/RedisMetadata.java/RedisMetadata/getTableHandle
class RedisMetadata:    @Override
    public RedisTableHandle getTableHandle(ConnectorSession session, SchemaTableName schemaTableName)
    {
        RedisTableDescription table = getDefinedTables().get(schemaTableName);
        if (table == null) {
            return null;
        }

        // check if keys are supplied in a zset
        // via the table description doc
        String keyName = null;
        if (table.getKey() != null) {
            keyName = table.getKey().getName();
        }

        return new RedisTableHandle(
                schemaTableName.getSchemaName(),
                schemaTableName.getTableName(),
                getDataFormat(table.getKey()),
                getDataFormat(table.getValue()),
                keyName);
    }