text: from kivy.app import App
  from kivy.clock import Clock
  from kivymd.toolbar import Toolbar
  
  from etheroll.utils import load_kv_from_py
  
  load_kv_from_py(__file__)
  
  
  class CustomToolbar(Toolbar):
      """
      Toolbar with helper method for loading default/back buttons.
      """
  
      def __init__(self, **kwargs):
          super(CustomToolbar, self).__init__(**kwargs)
          Clock.schedule_once(self.load_default_buttons)
  
      def load_default_buttons(self, dt=None):
          app = App.get_running_app()
          self.left_action_items = [
              ['menu', lambda x: app.root.navigation.toggle_nav_drawer()]]
          self.right_action_items = [[
                  'dots-vertical',
                  lambda x: app.root.navigation.toggle_nav_drawer()]]
  
      def load_back_button(self, function):
          self.left_action_items = [['arrow-left', lambda x: function()]]
  