'Apply changes callback'

def apply_changes(self):

    if self.is_modified:
        self.save_to_conf()
        if (self.apply_callback is not None):
            self.apply_callback()
        if (self.CONF_SECTION == u'main'):
            self._save_lang()
        for restart_option in self.restart_options:
            if (restart_option in self.changed_options):
                self.prompt_restart_required()
                break
        self.set_modified(False)
