module H:sig
..end
type('a, 'b)
t =('a, 'b) Hashtbl.t
val create : unit -> ('a, 'b) Hashtbl.t
val clear : ('a, 'b) Hashtbl.t -> unit
val get_assoc : ('a, 'b) Hashtbl.t -> 'a -> 'b
val update_assoc : ('a, 'b) Hashtbl.t -> 'a -> 'b -> unit
val remove_assoc : ('a, 'b) Hashtbl.t -> 'a -> unit
val assoc_to_keys : ('a, 'b) Hashtbl.t -> 'a list
val assoc_to_list : ('a, 'b) Hashtbl.t -> 'b list
val assoc_size : ('a, 'b) Hashtbl.t -> int
val filter : ('a, 'b) Hashtbl.t -> ('a * 'b -> bool) -> ('a * 'b) list