+test = 0
+
+def test_data (data, n_rcvd):
+ n_read = len (data);
+ for i in range(n_read):
+ expected = (n_rcvd + i) & 0xff
+ byte_got = ord (data[i])
+ if (byte_got != expected):
+ print("Difference at byte {}. Expected {} got {}"
+ .format(n_rcvd + i, expected, byte_got))
+ return n_read