def _keys_impl(self):
        """This function exists so __len__ can be implemented more efficiently,
        saving one list creation from an iterator.

        Using this for Python 2's ``dict.keys`` behavior would be useless since
        `dict.keys` in Python 2 returns a list, while we have a set here.
        """
        rv = set()
        for d in self.dicts:
            rv.update(iterkeys(d))
        return rv
This function exists so __len__ can be implemented more efficiently,
        saving one list creation from an iterator.

        Using this for Python 2's ``dict.keys`` behavior would be useless since
        `dict.keys` in Python 2 returns a list, while we have a set here.
        
Solutions/CyberArkAudit/Data Connectors/.python_packages/lib/site-packages/azure/functions/_thirdparty/werkzeug/datastructures.py