Parameter Make.1-R

module Key : sig ... end
module Common_args : Core_kernel.T
type t
val open_ : Key.t -> Common_args.t -> t Async_kernel.Deferred.Or_error.t
val close : t -> unit Async_kernel.Deferred.t
val close_finished : t -> unit Async_kernel.Deferred.t
val has_close_started : t -> bool

has_close_started t should return true iff close t has been called, even if close_finished has not been determined.