`sig
type t
val create :
?runtime_begin:(int ->
Runtime_events.Timestamp.t ->
Runtime_events.runtime_phase -> unit) ->
?runtime_end:(int ->
Runtime_events.Timestamp.t ->
Runtime_events.runtime_phase -> unit) ->
?runtime_counter:(int ->
Runtime_events.Timestamp.t ->
Runtime_events.runtime_counter -> int -> unit) ->
?alloc:(int -> Runtime_events.Timestamp.t -> int array -> unit) ->
?lifecycle:(int ->
Runtime_events.Timestamp.t ->
Runtime_events.lifecycle -> int option -> unit) ->
?lost_events:(int -> int -> unit) -> unit -> Runtime_events.Callbacks.t
end`