`?extra_match:(exn -> bool) ->
(Unixqueue.operation * float) list ->
Unixqueue.event_system ->
object
method abort : unit -> unit
method event_system : Unixqueue.event_system
method group : Unixqueue.group
method request_notification : (unit -> bool) -> unit
method request_proxy_notification :
(Unixqueue.event engine -> bool) -> unit
method restart : unit -> unit
method state : Unixqueue.event engine_state
end`