code: def get_item_bank_session(self):
          
          if not self.supports_item_bank():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.ItemBankSession(runtime=self._runtime)
docs: Gets the ``OsidSession`` associated with the item banking service.
  
          return: (osid.assessment.ItemBankSession) - an
                  ``ItemBankSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_item_bank()`` is ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_item_bank()`` is ``true``.*