Java serialVersionUid and contained classes

Consider the below code:

class TestSUid implements Serializable {

    private static final Long serialVersionUID =101010101010L; 
    private String title;
    private Error error;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Error getError() {
        return error;
    }

    public void setError(Error error) {
        this.error = error;
    }
}

class Error implements Serializable {
    private String title;
    private String message;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

Now my objective is to serialize the TestSUid class so that I can enable offline caching. I am confused on the part if I need to add a serialVersionUID to my Error class as well. What if I need to update the error class in future would updating the TestSUid version id be enough?

I have gone through the reference at: https://docs.oracle.com/javase/8/docs/platform/serialization/spec/version.html#a6678

But still dont feel entirely confident.