`object
method charset : string
method content_type :
unit -> string * (string * Netmime_string.s_param) list
method filename : string option
method finalize : unit -> unit
method name : string
method open_value_rd : unit -> Netchannels.in_obj_channel
method open_value_wr : unit -> Netchannels.out_obj_channel
method representation : representation
method ro : bool
method set_value : string -> unit
method store : store
method value : string
end`