ydb/yql/essentials/tests/s-expressions/suites/Aggregation/AggregateWithoutTraits.yql

(
(let world (block '(
  (let x (Read! world (DataSource '"yt" '"plato") (Key '('table (String '"Input"))) '('"key" '"subkey" '"value") '()))
  (let world (Left! x))
  (let input (Right! x))
  (let output (block '(
    (let select (block '(
      (let core input)
      (let core (block '(
        (return (Aggregate core '('key 'value) '()))
      )))
      (let core (FlatMap core (lambda '(row) (block '(
        (let res (Struct))
        (let res (AddMember res '"key" (Member row 'key)))
        (let res (AddMember res '"value" (Member row 'value)))
        (let res (AsList res))
        (return res)
      )))))
      (let core (Sort core '((Bool 'true) (Bool 'true)) (lambda '(x) '((Member x 'key) (Member x 'value)) )))
      (return core)
    )))
    (return select)
  )))
  (let world (block '(
    (let result_sink (DataSink 'result))
    (let world (Write! world result_sink (Key) output '('('type))))
    (return (Commit! world result_sink))
  )))
  (return world)
)))
(let world (block '(
  (let plato_sink (DataSink '"yt" '"plato"))
  (let world (Commit! world plato_sink))
  (return world)
)))
(return world)
)