exception ObjectNotFound of Bag.message
-val set_entry: (Bag.entry -> 'a) -> Bag.entry -> 'a
+val set_entity: (Bag.entity -> 'a) -> Bag.entity -> 'a
-val get_entry: (Bag.entry -> 'a) -> Bag.uri -> 'a
+val get_entity: (Bag.entity -> 'a) -> Bag.uri -> 'a