@Test
public void isSafeString() {

    Assert.assertEquals(true, StringUtil.isSafeString("abcdefghijklmnopqrstuvwzwz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"));
    Assert.assertEquals(false, StringUtil.isSafeString(" "));
    Assert.assertEquals(false, StringUtil.isSafeString("\n"));
    Assert.assertEquals(false, StringUtil.isSafeString("\t"));
    Assert.assertEquals(false, StringUtil.isSafeString("\r"));
}