`sig type key = T.t type 'a t = 'a Hashtbl.Make(T).t val create : int -> 'a t val clear : 'a t -> unit val reset : 'a t -> unit val copy : 'a t -> 'a t val add : 'a t -> key -> 'a -> unit val remove : 'a t -> key -> unit val find : 'a t -> key -> 'a val find_all : 'a t -> key -> 'a list val replace : 'a t -> key -> 'a -> unit val mem : 'a t -> key -> bool val iter : (key -> 'a -> unit) -> 'a t -> unit val filter_map_inplace : (key -> 'a -> 'a option) -> 'a t -> unit val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b val length : 'a t -> int val stats : 'a t -> Hashtbl.statistics val to_list : 'a Identifiable.S.t -> (Identifiable.S.T.t * 'a) list val of_list : (Identifiable.S.T.t * 'a) list -> 'a Identifiable.S.t val to_map : 'a Identifiable.S.t -> 'a Identifiable.S.Map.t val of_map : 'a Identifiable.S.Map.t -> 'a Identifiable.S.t val memoize : 'a Identifiable.S.t -> (key -> 'a) -> key -> 'a val map : 'a Identifiable.S.t -> ('a -> 'b) -> 'b Identifiable.S.t end`