Crud Rookie Update object using API (In Android Studio)

Apologies in advance I am very new to coding and self taught so I am finding myself running in to lots of roadblocks working through things (but also lots that is thankfully very intuitive).
I am working in android studio in Java
I have done all the other Crud Rookie missions but cant update object using API.

My API objects/Java Class have a name and surname only currently

There is an example posted by Mark Piller 1st Sep 2019 that provides the Java code for updating the name for someone in a Person class (has age, name, birth date) but is set up to modify the name, so i imagine my simpler class (which has name) should be fine too.

when i try use the code as below (just copied and pasted from the above Mark Piller page) :

final AsyncCallback<Person> updateResponder = new AsyncCallback<Person>() {
   @Override
   public void handleResponse(Person updatedPerson) {
       Log.i(TAG, "Person's name after update " + updatedPerson.name);
   }

   @Override
   public void handleFault(BackendlessFault fault) {
       Log.e(TAG, fault.getMessage());
   }
};

Backendless.Data.of(Person.class).findLast(new AsyncCallback<Person>() {
   @Override
   public void handleResponse(Person person) {
       Log.i(TAG, "Loaded object. Name - " + person.name);
       person.name = "Frankie";
       Backendless.Data.of(Person.class).save(person, updateResponder);
   }

   @Override
   public void handleFault(BackendlessFault fault) {
       Log.i(TAG, fault.getMessage());
   }
});

I get an issue with the TAG part, I have no idea what a tag is at all and cant find it through searching online.

What should i change the TAG part to, or is it not meant to be changed and the error is more deep than this?
Thanks in advance for your advice

Hello, @Leslie_Harding

Here you can read about Log and TAG - https://developer.android.com/reference/android/util/Log

Tell us, if that dont solve your issue.

Regards, DIma.

Just an update i was able to get it to work with the above link and info, thanks for your time
Les