class type char_output_channel = object .. end
Character(byte) output channel. Have the same interface of octet
input channel of http://www.ocaml-programming.de/rec/IO-Classes.html
All channels of Camomile having this interface must confirm the
behaviour defined in the recommendation above. In addition, all
channels are assumed to be blocking. If you supply a non-blocking
channel to Camomile API, the outcome is undefined.
method output : string -> int -> int -> int
method flush : unit -> unit
method close_out : unit -> unit