docs: def expose_finish(self, *args):
          """Finish drawing process
          """
          # Obtain a reference to the OpenGL drawable
          # and rendering context.
          gldrawable = self.get_gl_drawable()
          # glcontext = self.get_gl_context()
  
          if not gldrawable:
              return
  
          # Put the buffer on the screen!
          if gldrawable.is_double_buffered():
              gldrawable.swap_buffers()
          else:
              glFlush()
  
          # OpenGL end
          gldrawable.gl_end()