execute promises step by step concode_field_sep PlaceHolder placeHolder concode_field_sep Promise<Tuple2<T1,T2>> tuple concode_elem_sep Promise<Tuple3<T1,T2,T3>> tuple concode_elem_sep Promise<Tuple4<T1,T2,T3,T4>> tuple concode_elem_sep Promise<T> log
Promise function ( List < Supplier < Promise < T >>> arg0 ) { if ( arg0 . size ( ) == 0 ) { return Promise . success ( null ) ; } return arg0 . remove ( 0 ) . get ( ) . flatMap ( v -> traverse ( arg0 ) ) ; }