ydb/yql/essentials/tests/s-expressions/suites/InMem/ByteAt.yqls

(
#comment
(let config (DataSource 'config))

(let res_sink (DataSink 'result))
(let world (Write! world res_sink (Key) (ByteAt (String 'ab) (Uint32 '1)) '('('type))))
(let world (Write! world res_sink (Key) (ByteAt (String 'ab) (Uint32 '2)) '('('type))))
(let world (Write! world res_sink (Key) (ByteAt (Just (String 'ab)) (Uint32 '1)) '('('type))))
(let world (Write! world res_sink (Key) (ByteAt (Just (String 'ab)) (Uint32 '2)) '('('type))))
(let world (Write! world res_sink (Key) (ByteAt (Nothing (OptionalType (DataType 'String))) (Uint32 '1)) '('('type))))

(let world (Commit! world res_sink))
(return world)
)