def get_objective_bank_hierarchy(self):
<EOL>if self._catalog_session is not None:<EOL><INDENT>return self._catalog_session.get_catalog_hierarchy()<EOL><DEDENT>return self._hierarchy_session.get_hierarchy()<EOL>
Gets the hierarchy associated with this session.

        return: (osid.hierarchy.Hierarchy) - the hierarchy associated
                with this session
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*