`sig
type t
val make :
connection:OBus_connection.t -> message:OBus_message.t -> OBus_context.t
val get : unit -> OBus_context.t
val key : OBus_context.t Lwt.key
val connection : OBus_context.t -> OBus_connection.t
val sender : OBus_context.t -> OBus_peer.t
val destination : OBus_context.t -> OBus_peer.t
val flags : OBus_context.t -> OBus_message.flags
val serial : OBus_context.t -> OBus_message.serial
end`