How to use the khal.ui.__init__.U_Event function in khal

def refresh_titles(self):
        """refresh the titles of all events"""
        for uevent in self.body[1:]:
            if isinstance(uevent._original_widget, U_Event):
                uevent.original_widget.set_title()

def _search(self, search_term):
        """search for events matching `search_term"""
        self.window.backtrack()
        events = sorted(self.collection.search(search_term))
        event_list = []
        event_list.extend([
            urwid.AttrMap(
                U_Event(event, relative=False, conf=self._conf, delete_status=self.delete_status),
                'calendar ' + event.calendar, 'reveal focus')
            for event in events])
        events = EventListBox(
            urwid.SimpleFocusListWalker(event_list), parent=self.eventscolumn, conf=self._conf,
            delete_status=self.delete_status,
            toggle_delete_all=self.toggle_delete_all,
            toggle_delete_instance=self.toggle_delete_instance
        )
        events = EventColumn(pane=self, elistbox=events)
        ContainerWidget = linebox[self._conf['view']['frame']]
        columns = NColumns(
            [(self.lwidth, self.calendar), ContainerWidget(events)],
            dividechars=0,
            box_columns=[0, 0],
            outermost=True,
        )

def _search(self, search_term):
        """search for events matching `search_term"""
        self.window.backtrack()
        events = sorted(self.collection.search(search_term))
        event_list = []
        event_list.extend([
            urwid.AttrMap(
                U_Event(event, relative=False, conf=self._conf, delete_status=self.delete_status),
                'calendar ' + event.calendar, 'reveal focus')
            for event in events])
        events = EventListBox(
            urwid.SimpleFocusListWalker(event_list), parent=self.eventscolumn, conf=self._conf,
            delete_status=self.delete_status,
            toggle_delete_all=self.toggle_delete_all,
            toggle_delete_instance=self.toggle_delete_instance
        )
        events = EventColumn(pane=self, elistbox=events)
        ContainerWidget = linebox[self._conf['view']['frame']]
        columns = NColumns(
            [(self.lwidth, self.calendar), ContainerWidget(events)],
            dividechars=0,
            box_columns=[0, 0],
            outermost=True,
        )

def _get_events(self, day):
        """get all events on day, return a DateListBox of `U_Event()`s

        :type day: datetime.date
        """
        event_list = list()
        date_header = DateHeader(
            day=day,
            dateformat=self._conf['locale']['longdateformat'],
            conf=self._conf,
        )
        event_list.append(urwid.AttrMap(date_header, 'date'))
        self.events = sorted(self._collection.get_events_on(day))
        event_list.extend([
            urwid.AttrMap(
                U_Event(event, conf=self._conf, this_date=day, delete_status=self.delete_status),
                'calendar ' + event.calendar, 'reveal focus')
            for event in self.events])
        return urwid.BoxAdapter(
            DateListBox(urwid.SimpleFocusListWalker(event_list), date=day),
            (len(event_list) + 1) if self.events else 1
        )

def _get_events(self, day):
        """get all events on day, return a DateListBox of `U_Event()`s

        :type day: datetime.date
        """
        event_list = list()
        date_header = DateHeader(
            day=day,
            dateformat=self._conf['locale']['longdateformat'],
            conf=self._conf,
        )
        event_list.append(urwid.AttrMap(date_header, 'date'))
        self.events = sorted(self._collection.get_events_on(day))
        event_list.extend([
            urwid.AttrMap(
                U_Event(event, conf=self._conf, this_date=day, delete_status=self.delete_status),
                'calendar ' + event.calendar, 'reveal focus')
            for event in self.events])
        return urwid.BoxAdapter(
            DateListBox(urwid.SimpleFocusListWalker(event_list), date=day),
            (len(event_list) + 1) if self.events else 1
        )

def refresh_titles(self):
        """refresh the titles of all events"""
        for uevent in self.body[1:]:
            if isinstance(uevent._original_widget, U_Event):
                uevent.original_widget.set_title()