assertThat(StringUtil.defaultString("aaa", null), is("aaa"));
        assertThat(StringUtil.defaultString(null, null), is(nullValue()));
    }

    @Test
    public void testNewStringUnsafe() {
        assertNull(StringUtil.newStringUnsafe(null));
        char[] chars = new char[0];
        assertThat(StringUtil.newStringUnsafe(chars), is(""));
        chars = new char[] { 'a', 'b', 'c' };