module Hashtbl:sig..end
type ('a, 'b) t
val create : int -> ('a, 'b) tval get : ('a, 'b) t -> ('a, 'b) Hashtbl.tval add : ('a, 'b) t -> 'a -> 'b -> unitval find : ('a, 'b) t -> 'a -> 'bval mem : ('a, 'b) t -> 'a -> boolval remove : ('a, 'b) t -> 'a -> unitval replace : ('a, 'b) t -> 'a -> 'b -> unitval iter : ('a -> 'b -> unit) -> ('a, 'b) t -> unitval fold : ('a -> 'b -> 'c -> 'c) -> ('a, 'b) t -> 'c -> 'c