FIX: if multiple updates for one entity exist, the retrieve would result in an...

FIX: if multiple updates for one entity exist, the retrieve would result in an slim <Entity id='255'/> object

src/caosadvancedtools/cache.py

@@ -300,8 +300,10 @@ class Cache(AbstractCache):
         if entities is None:
             # TODO this might become a problem. If many entities are cached,
             # then all of them are retrieved here...
+            ids = [c_id for c_id, _ in res]
+            ids = set(ids)
             entities = db.Container()
-            entities.extend([db.Entity(id=c_id) for c_id, _ in res])
+            entities.extend([db.Entity(id=c_id) for c_id in ids])
             entities.retrieve()
 
         v = {c_id: c_version for c_id, c_version in res}