Batteries user guide : BatHashcons.Table

`sig type key type t val create : int -> BatHashcons.Table.t val clear : BatHashcons.Table.t -> unit val hashcons : BatHashcons.Table.t -> BatHashcons.Table.key -> BatHashcons.Table.key BatHashcons.hobj val iter : (BatHashcons.Table.key BatHashcons.hobj -> unit) -> BatHashcons.Table.t -> unit val fold : (BatHashcons.Table.key BatHashcons.hobj -> 'a -> 'a) -> BatHashcons.Table.t -> 'a -> 'a val count : BatHashcons.Table.t -> int end`