title: Kivy Button not displaying
body: <p>According to this code which I have seen in a youtube video there is two side by side Button shown in kivy screen but in my case there is blank screen. no button display.
  for helping thanks in advance .
  I am new in Python and kivy.</p>
  <pre><code>from kivy.app import App
  from kivy.lang import Builder
  from kivy.uix.button import Button
  from kivy.uix.boxlayout import BoxLayout
  from kivy.uix.widget import Widget
  
  
  class BoxLayoutExample(BoxLayout):
      def __init__(self, **kwargs):
          super().__init__(**kwargs)
          b1 = Button(text=&quot;Button A&quot;)
          b2 = Button(text=&quot;Button B&quot;)
          self.add_widget(b1)
          self.add_widget(b2)
  
  
  class MainWidget(Widget):
      pass
  
  
  class TheLabApp(App):
      pass
  
  
  TheLabApp().run()
  </code></pre>