public static boolean endsWith(CharSequence s, char c) {
        int len = s.length();
        return len > 0 && s.charAt(len - 1) == c;
    }
@Test
    public void testEndsWith() {
        assertFalse(StringUtil.endsWith("", 'u'));
        assertTrue(StringUtil.endsWith("u", 'u'));
        assertTrue(StringUtil.endsWith("-u", 'u'));
        assertFalse(StringUtil.endsWith("-", 'u'));
        assertFalse(StringUtil.endsWith("u-", 'u'));
    }