ydb/yql/essentials/tests/s-expressions/suites/Optimizers/CondenseOneItemStruct.yqls

(
(let config (DataSource 'config))

(let list (AsList (String 'a) (String 'b) (String 'c)))
(let data (Condense list (AddMember (Struct) 'z (String '"")) 
   (lambda '(item state) (Bool 'false))
   (lambda '(item state) 
       (AddMember 
          (Struct) 
          'z 
          (Concat (Member state 'z) item)))))
(let res_sink (DataSink 'result))
(let world (Write! world res_sink
    (Key)
    data '('('type))))

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