type 'a handler
= 'a -> unit
type ('a, 'b) handler2
= 'a -> 'b -> unit
type unsubscribe
= unit -> unit
val dispatch : 'a -> 'a handler list Stdlib.ref -> unit
val dispatch2 : 'a -> 'b -> ('a, 'b) handler2 list Stdlib.ref -> unit
val add : 'a handler -> 'a handler list Stdlib.ref -> unit -> unit
val add2 : ('a, 'b) handler2 -> ('a, 'b) handler2 list Stdlib.ref -> unit -> unit