Module Time.Pi

module type CLOCK = sig ... end
type Resource.pi +=
  1. | Clock : ('t, (module CLOCK with type t = 't and type time = 'time), [> 'time clock_ty ]) Resource.pi
val clock : (module CLOCK with type t = 't and type time = 'time) -> ('t, [> 'time clock_ty ]) Resource.handler