@abc.abstractmethod<EOL><INDENT>def get_bank_lookup_session(self):<DEDENT>
return<EOL>
Gets the OsidSession associated with the bank lookup service.

        :return: a ``BankLookupSession``
        :rtype: ``osid.assessment.BankLookupSession``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_bank_lookup() is false``

        *compliance: optional -- This method must be implemented if
        ``supports_bank_lookup()`` is true.*