val create : config:Server_config.t ‑> send:(Types.Envelope_with_next_hop.t ‑> unit Core.Or_error.t Async.Deferred.t) ‑> t Core.Or_error.t Async.Deferred.tval add : t ‑> original_msg:Types.Envelope.t ‑> Types.Envelope_with_next_hop.t list ‑> Types.Envelope.Id.t Core.Or_error.t Async.Deferred.tval flush : ?timeout:unit Async.Deferred.t ‑> t ‑> bool Async.Deferred.t