def append_request(self, request):
        self._content.update(request.to_representation())
update a plot trace with new data, avoiding complete redraw
dataset/ETHPy150Open Relrin/aiorest-ws/aiorest_ws/wrappers.py/Response.append_request--crossover with--dataset/ETHPy150Open xraypy/xraylarch/plugins/wx/plotter.py/_update_trace