Reorders renderers based on the defined draw order

def _reorder_renderers(self, plot, renderer, mapping):
        "Reorders renderers based on the defined draw order"
        renderers = dict({r: self.handles[r+'_glyph_renderer']
                          for r in mapping}, graph=renderer)
        other = [r for r in plot.renderers if r not in renderers.values()]
        graph_renderers = [renderers[k] for k in self._draw_order if k in renderers]
        plot.renderers = other + graph_renderers