How to use the pixiedust.display.display.Display function in pixiedust

def get(self):
        from pixiedust.display.display import Display
        class PixieDustDisplay(Display):
            def doRender(self, handlerId):
                pass
        self.set_header('Content-Type', 'text/javascript' if self.loadjs else 'text/css')
        disp = PixieDustDisplay({"gateway":"true"}, None)
        disp.callerText = "display(None)"
        self.write(disp.renderTemplate("pixiedust.js" if self.loadjs else "pixiedust.css"))
        self.finish()