code: def _shade_missing_label(self):
          
          # Start a drawing for the whole label.
          label = Drawing(float(self._lw), float(self._lh))
          label.add(self._clip_label)
  
          # Fill with a rectangle; the clipping path will take care of the borders.
          r = shapes.Rect(0, 0, float(self._lw), float(self._lh))
          r.fillColor = self.shade_missing
          r.strokeColor = None
          label.add(r)
  
          # Add the label to the page.
          label.shift(*self._calculate_edges())
          self._current_page.add(label)
docs: Helper method to shade a missing label. Not intended for external use.