code: def _reset_kind_map(cls):
      
      # Preserve "system" kinds, like __namespace__
      keep = {}
      for name, value in cls._kind_map.iteritems():
        if name.startswith('__') and name.endswith('__'):
          keep[name] = value
      cls._kind_map.clear()
      cls._kind_map.update(keep)
docs: Clear the kind map.  Useful for testing.