child process - this holds all the GUI elements

def child_task(self):
        '''child process - this holds all the GUI elements'''
        mp_util.child_close_fds()

        import matplotlib, platform
        if platform.system() != "Darwin":
            # on MacOS we can't set WxAgg here as it conflicts with the MacOS version
            matplotlib.use('WXAgg')

        from MAVProxy.modules.lib import wx_processguard
        from MAVProxy.modules.lib.wx_loader import wx

        app = wx.App(False)
        from MAVProxy.modules.lib import live_graph_ui
        app.frame = live_graph_ui.GraphFrame(state=self)
        app.frame.Show()
        app.MainLoop()