I have the following code to reverse a string, and I am considering to make test cases for it. I would like to know how to handle cases like when user input "\n", "\t" ?

```
private static String reverse2(String str) {
    if (str == null || str.length() == 0)
        return str;

    int start = 0;
    int end = str.length() - 1;

    char[] chars = str.toCharArray();
    while (start < end) {
        char tmp = chars[start];
        chars[start] = chars[end];
        chars[end] = tmp;

        start++;
        end--;
    }

    return String.valueOf(chars);
}

```