implement BaseStorage.data as property

ffstatus/basestorage.py

@@ -33,7 +33,20 @@ class BaseStorage(object):
     DATAKEY_VPN = '__VPN__'
     FIELDKEY_UPDATED = '__UPDATED__'
 
-    data = None
+    __data = None
+
+    @property
+    def data(self):
+        """Contains the data handled by this storage."""
+        return self.__data
+
+    @data.setter
+    def data(self, value):
+        """setter for data property"""
+        logging.debug('Setting new storage data (old=%d/new=%d items).',
+                      len(self.__data) if self.__data is not None else 0,
+                      len(value) if value is not None else 0)
+        self.__data = value
 
     def open(self):
         """