def hexDump(bytes):
    """ Useful utility; prints the string in hexadecimal.
	"""
    print('byte   0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F')
    num = len(bytes)
    for i in range(num):
        if i % 16 == 0:
            line = '%02X0 : ' % (i / 16)
        line += '%02X ' % ord(bytes[i])
        if (i + 1) % 16 == 0:
            print('%s: %s' % (line, repr(bytes[i - 15:i + 1])))
            line = ''
    bytes_left = num % 16
    if bytes_left:
        print('%s: %s' % (line.ljust(54), repr(bytes[-bytes_left:])))
