code: def DeregisterCredentials(cls, credentials):
      
      if credentials.type_indicator not in cls._credentials:
        raise KeyError(
            'Credential object not set for type indicator: {0:s}.'.format(
                credentials.type_indicator))
  
      del cls._credentials[credentials.type_indicator]
docs: Deregisters a path specification credentials.
  
      Args:
        credentials (Credentials): credentials.
  
      Raises:
        KeyError: if credential object is not set for the corresponding
            type indicator.