old_contents: import wx.lib
  # plot data
  (NewPlotEvent, EVT_NEW_PLOT) = wx.lib.newevent.NewEvent()
  # print the messages on statusbar
  (StatusEvent,  EVT_STATUS)   = wx.lib.newevent.NewEvent()
  #create a panel slicer 
  (SlicerPanelEvent, EVT_SLICER_PANEL)   = wx.lib.newevent.NewEvent()
  #print update paramaters for panel slicer 
  (SlicerParamUpdateEvent, EVT_SLICER_PARS_UPDATE)   = wx.lib.newevent.NewEvent()
  #update the slicer from the panel 
  (SlicerParameterEvent, EVT_SLICER_PARS)   = wx.lib.newevent.NewEvent()
  #slicer event
  (SlicerEvent, EVT_SLICER)   = wx.lib.newevent.NewEvent()
  # event containinG A DICTIONARY OF NAME and errors of selected data
  (ErrorDataEvent, ERR_DATA) = wx.lib.newevent.NewEvent()
new_contents: import wx.lib
  # plot data
  (NewPlotEvent, EVT_NEW_PLOT) = wx.lib.newevent.NewEvent()
  # print the messages on statusbar
  (StatusEvent,  EVT_STATUS)   = wx.lib.newevent.NewEvent()
  #create a panel slicer 
  (SlicerPanelEvent, EVT_SLICER_PANEL)   = wx.lib.newevent.NewEvent()
  #print update paramaters for panel slicer 
  (SlicerParamUpdateEvent, EVT_SLICER_PARS_UPDATE)   = wx.lib.newevent.NewEvent()
  #update the slicer from the panel 
  (SlicerParameterEvent, EVT_SLICER_PARS)   = wx.lib.newevent.NewEvent()
  #slicer event
  (SlicerEvent, EVT_SLICER)   = wx.lib.newevent.NewEvent()
  # event containinG A DICTIONARY OF NAME and errors of selected data
  (ErrorDataEvent, ERR_DATA) = wx.lib.newevent.NewEvent()
  ## event that that destroy a page associate with Data1D removed from the graph
  (RemoveDataEvent, EVT_REMOVE_DATA)   = wx.lib.newevent.NewEvent()
subject: add event to communicate info of plot removed from the graph to fitpanel