def test_isupper(self, size):
        chars = ''.join([ chr(c) for c in range(255) if not chr(c).islower() ])
        repeats = size // len(chars) + 2
        s = chars * repeats
        self.failUnless(s.isupper())
        s += 'a'
        self.failIf(s.isupper())