@abc.abstractmethod<EOL><INDENT>def get_installation_update_session(self, proxy):<DEDENT>
return<EOL>
Gets the ``OsidSession`` associated with the installation update service.

        :param proxy: a proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: an ``InstallationAdminSession``
        :rtype: ``osid.installation.InstallationUpdateSession``
        :raise: ``NullArgument`` -- ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_installation_update()`` is ``false``

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