def save_process():
    '''process for saving a graph'''
    from MAVProxy.modules.lib import wx_processguard
    from MAVProxy.modules.lib.wx_loader import wx
    from MAVProxy.modules.lib.wxgrapheditor import GraphDialog
    app = wx.App(False)
    frame = GraphDialog('Graph Editor',
                        mestate.last_graph,
                        save_callback)
    frame.ShowModal()
    frame.Destroy()
process for saving a graph