def test_count(self, size):
        SUBSTR = ' abc def ghi'
        s = '.' * size + SUBSTR
        self.assertEquals(s.count('.'), size)
        s += '.'
        self.assertEquals(s.count('.'), size + 1)
        self.assertEquals(s.count(' '), 3)
        self.assertEquals(s.count('i'), 1)
        self.assertEquals(s.count('j'), 0)