Fix for _init_cache and _load_source

__init__.py

     def _init_cache(self):
         load_cache = self._load_cache()
         uid = self._source_instance.uid() != self._uid()
-        data_version = self._source_instance.data_version() > self._data_version()
-        storage_version = self._storage_version() != self.STORAGE_VERSION
+        try:
+            data_version = self._source_instance.data_version() > self._data_version()
+        except TypeError:
+            data_version = True
+        try:
+            storage_version = self._storage_version() != self.STORAGE_VERSION
+        except TypeError:
+            storage_version = True
         #
         if not load_cache or uid or data_version or storage_version:
             if self._uid() is not None and uid:
         logger.debug('%s Loading all data from source - %s', self.LOG_PREFIX, repr(self._source_instance.keys()))
         for key in self._source_instance.keys():
             val = self._source_instance.get(key)
-            self._cached_props[self._key_filter(key)] = val
+            self._cached_props[self.DATA_TAG][self._key_filter(key)] = val
+            self._cached_props[self.AGE_TAG][self._key_filter(key)] = int(time.time())
 
     def _save_cache(self):
         with open(self._cache_filename, 'wb') as fh: