def test__read(self):
decoder = Decoder(b'abcdefg')
decoder.idx = 1
b = decoder._Decoder__read(3)
self.assertEqual(b, b'bcd', msg='__read(i) failed to copy the correct bytes.')
def test__read_exception(self):
decoder = Decoder(b'abcdefg')
decoder.idx = 1
with self.assertRaises(DecodingError):
decoder._Decoder__read(10)
