-module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status val set: dumpable_s -> dumpable_status -> dumpable_s end) :
- SerializerType with type dumpable_status = D.dumpable_s
+module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status
+ val set: dumpable_s -> dumpable_status -> dumpable_s val user : dumpable_s ->
+ string option end) :
+ SerializerType with type dumpable_status = D.dumpable_s