def get_qualifier_vault_assignment_session(self):
raise Unimplemented()<EOL>
Gets the session for assigning qualifier to vault mappings.

        return: (osid.authorization.QualifierVaultSession) - a
                ``QualifierVaultAssignmentSession``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented -
                ``supports_qualifier_vault_assignment()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_qualifier_vault_assignment()`` is ``true``.*