def _refresh_renderers(self):
        """ Refresh the renderers installed on the render window.

        """
        d = self.declaration
        old = self._current_renderers
        new = set(filter(None, [d.renderer] + d.renderers))
        to_remove = old.difference(new)
        to_add = new.difference(old)
        window = self.vtk_widget.GetRenderWindow()
        for r in to_remove:
            window.RemoveRenderer(r)
        for r in to_add:
            window.AddRenderer(r)
        self._current_renderers = new
dataset/ETHPy150Open nucleic/enaml/enaml/qt/qt_vtk_canvas.py/QtVTKCanvas._refresh_renderers/original