code: def add_toolitem(
      self, name, group, position, image_file, description, toggle
  ):
      if toggle:
          button = Gtk.ToggleToolButton()
      else:
          button = Gtk.ToolButton()
      button.set_label(name)
  
      if image_file is not None:
          image = Gtk.Image.new_from_gicon(
              Gio.Icon.new_for_string(image_file),
              Gtk.IconSize.LARGE_TOOLBAR,
          )
          button.set_icon_widget(image)
  
      if position is None:
          position = -1
  
      self._add_button(button, group, position)
      signal = button.connect("clicked", self._call_tool, name)
      button.set_tooltip_text(description)
      button.show_all()
      self._toolitems.setdefault(name, [])
      self._toolitems[name].append((button, signal))
  
imports: import functools
  import logging
  import os
  from pathlib import Path
  import matplotlib
  from matplotlib import _api, backend_tools, cbook
  from matplotlib.backend_bases import ToolContainerBase, CloseEvent, KeyEvent, LocationEvent, MouseEvent, ResizeEvent
  from gi.repository import Gio, GLib, GObject, Gtk, Gdk
  from .None import _backend_gtk
  from ._backend_gtk import _BackendGTK, _FigureCanvasGTK, _FigureManagerGTK, _NavigationToolbar2GTK, TimerGTK
label_desc: Use image node_id 2 for calling the ToolbarGTK3 obj's underlying member method code with example usage: obj.add_toolitem(name, group, position, image_file, description, toggle) without return types