Check if data is not None before caching

jsoncache/ApplicationCache.py

@@ -116,7 +116,7 @@ class ApplicationCache():
                     if cached_data is not None:
                         return unpacker(cached_data)
                 data = fun(*args, **kwargs)
-                if not cache_no_store:
+                if not cache_no_store and data is not None:
                     self.store(key=cache_key, data=packer(data))
                 return data
             return decorated