@abc.abstractmethod<EOL><INDENT>def register_for_changed_proficiency(self, proficiency_id):<DEDENT>
pass<EOL>
Registers for notification of an updated proficiency.

        ``ProficiencyReceiver.changedProficiencies()`` is invoked when
        the specified proficiency in this objective bank is changed.

        :param proficiency_id: the ``Id`` of the ``Proficiency`` to monitor
        :type proficiency_id: ``osid.id.Id``
        :raise: ``NullArgument`` -- ``proficiency_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*