code: def check_dirty(self):
          '''
          .. versionchanged:: 0.20
              Do not log size change.
          '''
          if self._dirty_size is None:
              if self._dirty_render:
                  self.render()
                  self._dirty_render = False
              if self._dirty_draw:
                  self.draw()
                  self._dirty_draw = False
              return True
          width, height = self._dirty_size
          self._dirty_size = None
          self.reset_canvas(width, height)
          self._dirty_render = True
          self._dirty_draw = True
          return Truf check_dirty(self):
          '''
          .. versionchanged:: 0.20
              Do not log size change.
          '''
          if self._dirty_size is None:
              if self._dirty_render:
                  self.render()
                  self._dirty_render = False
              if self._dirty_draw:
                  self.draw()
                  self._dirty_draw = False
              return True
          width, height = self._dirty_size
          self._dirty_size = None
          self.reset_canvas(width, height)
          self._dirty_render = True
          self._dirty_draw = True
          return True
docs: .. versionchanged:: 0.20
              Do not log size change.