`sig
type in_channel
val open_in : string -> Gzip.in_channel
val open_in_chan : Stdlib.in_channel -> Gzip.in_channel
val input_char : Gzip.in_channel -> char
val input_byte : Gzip.in_channel -> int
val input : Gzip.in_channel -> bytes -> int -> int -> int
val really_input : Gzip.in_channel -> bytes -> int -> int -> unit
val close_in : Gzip.in_channel -> unit
val dispose : Gzip.in_channel -> unit
type out_channel
val open_out : ?level:int -> string -> Gzip.out_channel
val open_out_chan : ?level:int -> Stdlib.out_channel -> Gzip.out_channel
val output_char : Gzip.out_channel -> char -> unit
val output_byte : Gzip.out_channel -> int -> unit
val output : Gzip.out_channel -> bytes -> int -> int -> unit
val output_substring : Gzip.out_channel -> string -> int -> int -> unit
val close_out : Gzip.out_channel -> unit
val flush : Gzip.out_channel -> unit
val flush_continue : Gzip.out_channel -> unit
exception Error of string
end`