code: def DeregisterPathSpec(cls, path_spec_type):
      
      type_indicator = path_spec_type.TYPE_INDICATOR
      if type_indicator not in cls._path_spec_types:
        raise KeyError(
            'Path specification type: {0:s} not set.'.format(type_indicator))
  
      del cls._path_spec_types[type_indicator]
  
      if type_indicator in cls._system_level_type_indicators:
        del cls._system_level_type_indicators[type_indicator]
docs: Deregisters a path specification.
  
      Args:
        path_spec_type (type): path specification type.
  
      Raises:
        KeyError: if path specification is not registered.