Does not set decompressobj.unused_data

In the following example, the unused_data attribute of the decompressor object should be "some more", but it isn't:

$ cat test.py
import lzma

compr = lzma.LZMACompressor(options={ 'level': 7 })

fh = open('/dev/urandom', 'rb')
buf = compr.compress(fh.read(10*1024))
buf += compr.flush()
buf += 'some more'

decompr = lzma.LZMADecompressor()
decompr.decompress(buf)

print len(decompr.unused_data)

$ python test.py
0