App.ActiveDocument.addObject("Sketcher::SketchObjectPython")
skf=SketchFeatureTemplate.SketchFeature(s) s.ViewObject.Proxy=0

# Sketcher Python Object 
import FreeCAD, FreeCADGui, Sketcher
App = FreeCAD
Gui = FreeCADGui

class SketchFeature:					# class SketcherClass: in wmayer's example
  def __init__(self, obj):
      obj.addProperty("App::PropertyLinkList","Sketches","Sketches","Master Sketches")
      obj.Proxy = self
  def execute(self, fp):
      FreeCAD.Console.PrintMessage("Execute completed before recompute ")
      fp.recompute()					# when used inside the execute() method of a custom feature class it invokes the method of the C++ base class
  def onChanged(self, fp, prop):
      '''Do something when a property has changed'''
      FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
#  def __setstate__(self, state):
  def __setstate__(self, res):
#      self.object.setEditorMode("MapMode",1)	# Not OK
#      self.Object.setEditorMode("MapMode",1)	# Not OK
#      self.setEditorMode("Constraints",2)	# Not OK
      return None