def test(polys, ber, message=None, print_flag=False):
if message == None:
f = open('message.txt', 'rb') # holds a 1000-bit binary string
message = f.read().strip()
e = Encoder(polys, message, ber, print_flag=print_flag)
encoded = e.encoded
sent = e.send()
t = Trellis(polys, sent)
decoded = t.decode_message()
if print_flag:
print 'Message: %s' % message
print 'Decoded: %s' % decoded
return hamming_distance(message, decoded)
