Jenis serikat pekerja; Persatuan[X, Y] setara dengan X | Y dan berarti X atau Y.
typing.Union
Union[Union[int, str], float] == Union[int, str, float]
Union[int] == int The constructor actually returns int
Union[int, str, int] == Union[int, str] == int | str
Union[int, str] == Union[str, int]