`sig
type 'a t
exception Empty
val create : unit -> 'a Queue.t
val add : 'a -> 'a Queue.t -> unit
val push : 'a -> 'a Queue.t -> unit
val take : 'a Queue.t -> 'a
val take_opt : 'a Queue.t -> 'a option
val pop : 'a Queue.t -> 'a
val peek : 'a Queue.t -> 'a
val peek_opt : 'a Queue.t -> 'a option
val top : 'a Queue.t -> 'a
val clear : 'a Queue.t -> unit
val copy : 'a Queue.t -> 'a Queue.t
val is_empty : 'a Queue.t -> bool
val length : 'a Queue.t -> int
val iter : ('a -> unit) -> 'a Queue.t -> unit
val fold : ('b -> 'a -> 'b) -> 'b -> 'a Queue.t -> 'b
val transfer : 'a Queue.t -> 'a Queue.t -> unit
val to_seq : 'a Queue.t -> 'a Stdlib.Seq.t
val add_seq : 'a Queue.t -> 'a Stdlib.Seq.t -> unit
val of_seq : 'a Stdlib.Seq.t -> 'a Queue.t
end`