code: def add_item(self, *args, **kwargs):
          
          try:
              self._get_provider_session('assessment_basic_authoring_session').add_item(*args, **kwargs)
          except InvalidArgument:
              self._get_sub_package_provider_session(
                  'assessment_authoring', 'assessment_part_item_design_session').add_item(*args, **kwargs)
docs: Pass through to provider methods.