Fills **Verbose_Level_ComboBox** Widget.

def __Verbose_Level_comboBox_set_ui(self):
        """
        Fills **Verbose_Level_ComboBox** Widget.
        """

        self.Verbose_Level_comboBox.clear()
        LOGGER.debug("> Available verbose levels: '{0}'.".format(Constants.verbosity_labels))
        self.Verbose_Level_comboBox.insertItems(0, QStringList(Constants.verbosity_labels))
        self.__engine.verbosity_level = foundations.common.get_first_item(
            self.__settings.get_key("Settings", "verbosity_level").toInt())
        self.Verbose_Level_comboBox.setCurrentIndex(self.__engine.verbosity_level)