Items should be compared separately
Sort entries if the 'merged' is a Feed object
Specialized list mixin for Entry objects
Use the function in EntryList
passive is not appropriate for the function name
PEP 8
rv should be EntryList object
Add EntryList to __all__ for documentation
Merge branch 'master' into bugs
Add test code for feed_id using category

It gives feed_id as None.
Fix bug: feed_id as None