How to use the khal.ui.widgets.NColumns function in khal

def _rebuild_edit(self):
        firstline = NColumns([
            (13, self.repeat_box),
            (11, self.recurrence_choice),
            (11, self.interval_edit),
        ])
        lines = [firstline]

        if self.recurrence_choice.active == "weekly":
            lines.append(self.weekday_checks)
        if self.recurrence_choice.active == "monthly":
            lines.append(self.monthly_choice)

        nextline = [(16, self.until_choice)]
        if self.until_choice.active == "Until":
            nextline.append((20, self.until_edit))
        elif self.until_choice.active == "Repetitions":
            nextline.append((4, self.repetitions_edit))

raw_start_time_widget, align='left', width=self._timewidth + 1, left=1)

            raw_end_time_widget = ValidatedEdit(
                dateformat=self.conf['locale']['timeformat'],
                EditWidget=TimeWidget,
                validate=self._validate_end_time,
                edit_text=self.enddt.strftime(self.conf['locale']['timeformat']),
            )
            self.widgets.endtime = urwid.Padding(
                raw_end_time_widget, align='left', width=self._timewidth + 1, left=1)

        columns = NPile([
            self.checkallday,
            NColumns([(5, urwid.Text('From:')), (self._datewidth, self.widgets.startdate), (
                timewidth, self.widgets.starttime)], dividechars=1),
            NColumns(
                [(5, urwid.Text('To:')), (self._datewidth, self.widgets.enddate),
                 (timewidth, self.widgets.endtime)],
                dividechars=1)
        ], focus_item=1)
        urwid.WidgetWrap.__init__(self, columns)

def scrollable_dialog(self, text, buttons=None, title="Press `ESC` to close this window"):
        """Open a scrollable dialog box.

        :param text: Text to appear as the body of the Dialog box
        :type text: str
        :param buttons: list of tuples of button labels and functions to call
            when the button is pressed
        :type buttons: list(str, callable)
        """
        body = urwid.ListBox([urwid.Text(line) for line in text.splitlines()])
        if buttons:
            buttons = NColumns(
                [urwid.Button(label, on_press=func) for label, func in buttons],
                outermost=True,
            )
            content = urwid.LineBox(urwid.Pile([body, ('pack', buttons)]))
        else:
            content = urwid.LineBox(urwid.Pile([body]))

        # put the title on the upper line
        over = urwid.Overlay(
            urwid.Text(" " + title + " "), content, 'center', len(title) + 2, 'top', None,
        )
        overlay = urwid.Overlay(
            over, self, 'center', ('relative', 70), 'middle', ('relative', 70), None)
        self.window.open(overlay)

calendar = CalendarWidget(
            on_date_change=self.eventscolumn.original_widget.set_focus_date,
            keybindings=self._conf['keybindings'],
            on_press={key: self.new_event for key in self._conf['keybindings']['new']},
            firstweekday=self._conf['locale']['firstweekday'],
            weeknumbers=self._conf['locale']['weeknumbers'],
            monthdisplay=self._conf['view']['monthdisplay'],
            get_styles=collection.get_styles
        )
        if self._conf['view']['dynamic_days']:
            elistbox.set_focus_date_callback = calendar.set_focus_date
        else:
            elistbox.set_focus_date_callback = lambda _: None
        self.calendar = ContainerWidget(calendar)
        self.lwidth = 31 if self._conf['locale']['weeknumbers'] == 'right' else 28
        columns = NColumns(
            [(self.lwidth, self.calendar), self.eventscolumn],
            dividechars=0,
            box_columns=[0, 1],
            outermost=True,
        )
        Pane.__init__(self, columns, title=title, description=description)

def _rebuild_edit_no_repeat(self):
        lines = [NColumns([(13, self.repeat_box)])]
        self._refill_contents(lines)

def __init__(self, startdt, selected_days):

        self._weekday_boxes = {day: urwid.CheckBox(day, state=False) for day in WEEKDAYS}
        weekday = startdt.weekday()
        self._weekday_boxes[WEEKDAYS[weekday]].state = True
        self.weekday_checks = NColumns([(7, self._weekday_boxes[wd]) for wd in WEEKDAYS])
        for day in selected_days:
            self._weekday_boxes[day].state = True
        urwid.WidgetWrap.__init__(self, self.weekday_checks)

def keypress(self, size, key):
                if key == 'enter':
                    search_func(self.text)
                else:
                    return super().keypress(size, key)

        search_field = Search('')

        def this_func(_):
            search_func(search_field.text)

        lines = []
        lines.append(urwid.Text('Please enter a search term (Escape cancels):'))
        lines.append(search_field)
        buttons = NColumns([urwid.Button('Search', on_press=this_func),
                            urwid.Button('Abort', on_press=abort_func)])
        lines.append(buttons)
        content = NPile(lines, outermost=True)
        urwid.WidgetWrap.__init__(self, urwid.LineBox(content))