code: def get_bank_lookup_session(self):
          
          if not self.supports_bank_lookup():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.BankLookupSession(runtime=self._runtime)
docs: Gets the OsidSession associated with the bank lookup service.
  
          return: (osid.assessment.BankLookupSession) - a
                  ``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.*