MultipartInputStream.nextPart

Obtains an input stream for the next part.

When dealing with a multipart response the input stream needs to be wrapped in a #SoupMultipartInputStream and this function or its async counterpart need to be called to obtain the first part for reading.

After calling this function, [soup.multipart_input_stream.MultipartInputStream.getHeaders] can be used to obtain the headers for the first part. A read of 0 bytes indicates the end of the part; a new call to this function should be done at that point, to obtain the next part.