How to use the ipyvuetify.Col function in ipyvuetify

drawer = v.NavigationDrawer(v_model=False, absolute=True, right=True,
                                children=[sidebar_button,
                                          options_panel], width="min-content")

    toolbar = v.Toolbar(dense=True, class_='elevation-0',
                        children=[v.ToolbarItems(children=[viewer.toolbar_selection_tools,
                                                           viewer.toolbar_selection_mode,
                                                           viewer.toolbar_active_subset]),
                                  v.Spacer(),
                                  sidebar_button])

    layout = v.Html(tag='div', children=[
        toolbar,
        v.Row(no_gutters=True, children=[
            v.Col(cols=12, children=[viewer.figure_widget]),
            v.Col(cols=12, children=[viewer.output_widget])
        ]),
        drawer
    ])

    return layout

drawer = v.NavigationDrawer(v_model=False, absolute=True, right=True,
                                children=[sidebar_button,
                                          options_panel], width="min-content")

    toolbar = v.Toolbar(dense=True, class_='elevation-0',
                        children=[v.ToolbarItems(children=[viewer.toolbar_selection_tools,
                                                           viewer.toolbar_selection_mode,
                                                           viewer.toolbar_active_subset]),
                                  v.Spacer(),
                                  sidebar_button])

    layout = v.Html(tag='div', children=[
        toolbar,
        v.Row(no_gutters=True, children=[
            v.Col(cols=12, children=[viewer.figure_widget]),
            v.Col(cols=12, children=[viewer.output_widget])
        ]),
        drawer
    ])

    return layout