code: def get_all_feature_flags(self, user_email=None):
          
          query_parameters = {}
          if user_email is not None:
              query_parameters['userEmail'] = self._serialize.query('user_email', user_email, 'str')
          response = self._send(http_method='GET',
                                location_id='3e2b80f8-9e6f-441e-8393-005610692d9c',
                                version='5.0-preview.1',
                                query_parameters=query_parameters)
          return self._deserialize('[FeatureFlag]', self._unwrap_collection(response))
docs: GetAllFeatureFlags.
          [Preview API] Retrieve a listing of all feature flags and their current states for a user
          :param str user_email: The email of the user to check
          :rtype: [FeatureFlag]