code: def print_diff(self, ignore=[]):
          
          # ignore this and the caller frame
          ignore.append(inspect.currentframe()) #PYCHOK change ignore
          diff = self.get_diff(ignore)
          print("Added objects:")
          summary.print_(summary.summarize(diff['+']))
          print("Removed objects:")
          summary.print_(summary.summarize(diff['-']))
          # manual cleanup, see comment above
          del ignore[:]
docs: Print the diff to the last time the state of objects was measured.
  
          keyword arguments
          ignore -- list of objects to ignore