include Hashtbl.S with type key = T.t and type 'a t = 'a Hashtbl.Make(T).t
val add : 'a t -> key -> 'a -> unit
val remove : 'a t -> key -> unit
val find : 'a t -> key -> 'a
val find_opt : 'a t -> key -> 'a option
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 to_seq_values : 'a t -> 'a Seq.t
val add_seq : 'a t -> (key * 'a) Seq.t -> unit
val replace_seq : 'a t -> (key * 'a) Seq.t -> unit
val to_list : 'a t -> (T.t * 'a) list
val of_list : (T.t * 'a) list -> 'a t
val memoize : 'a t -> (key -> 'a) -> key -> 'a
val map : 'a t -> ('a -> 'b) -> 'b t