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