# new BatIO.out_channel |- Csv.to_out_obj;;
Error: This expression has type Csv.out_obj_channel -> Csv.out_channel
       but an expression was expected of type BatIO.out_channel -> 'a
       Type
         Csv.out_obj_channel =
           < close_out : unit -> unit; output : string -> int -> int -> int >
       is not compatible with type
         BatIO.out_channel =
           < close_out : unit -> unit; flush : unit -> unit;
             output : string -> int -> int -> int > 
       The first object type has no method flush