…alue set by the user is not lost.

Also, fix a bug where a second iteration on the cursor would results in no content at all, because of self.retrieved not being reset. This is not an useful information outside of the iteration algo so self.retrieved was made local to reduce impact.
Adding .vscode in .gitignore

…ursor-skip-retrieved

…sts/helpers.py.

The last page generated was not getting the right start_element and causing a StopIteration when the generated collection was assigned as a side_effect on a cursor.

…o made.

The logic handling skip (if defined) and limit (if defined) has been transfered from __iter__ to iter_pages to avoid unecessary round-trips with AppNexus API.
Add unit tests around that logic and revamp of the helpers that generate collections when mocking client.get results.

…ing helpers

… mock_ordered_cursor