Record steps of WebDriverAgent

def patch_wda(self):
        """
        Record steps of WebDriverAgent
        """
        import wda

        def _click(that):
            rawx, rawy = that.bounds.center
            x, y = self.d.scale*rawx, self.d.scale*rawy
            screen_before = self._save_screenshot()
            orig_click = pt.get_original(wda.Selector, 'click')
            screen_after = self._save_screenshot()
            self.add_step('click',
                screen_before=screen_before,
                screen_after=screen_after,
                position={'x': x, 'y': y})
            return orig_click(that)

        pt.patch_item(wda.Selector, 'click', _click)