@abc.abstractmethod<EOL><INDENT>def get_item_bank_session(self):<DEDENT>
return<EOL>
Gets the ``OsidSession`` associated with the item banking service.

        :return: an ``ItemBankSession``
        :rtype: ``osid.assessment.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``.*