> Note that .join() has a slightly different behaviour:
> 
> >>> b"".join([bytearray(), b""])
> b''
> >>> bytearray().join([bytearray(), b""])
> bytearray(b'')
> >>> b"".join([bytearray(), memoryview(b"")])
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: sequence item 1: expected bytes, memoryview found

I thinks this is worth fixing. Is there an issue already?