assertFalse(StringUtil.isNumber("aaaBBBccc"));
        assertFalse(StringUtil.isNumber("０１２３４５６７８９"));
        assertFalse(StringUtil.isNumber(""));
        assertFalse(StringUtil.isNumber("01234abcdef"));
        assertFalse(StringUtil.isNumber("abcdef01234"));
    }

    /**
     *
     */
    @Test
    public void testIsEmpty() {
        assertTrue(StringUtil.isEmpty(null));