GitHub Copilot emits GPL code
As long as the AI doesn't produce this function, you're fine:     private static void rangeCheck(int arrayLen, int fromIndex, int toIndex {
       if (fromIndex > toIndex)
          throw new IllegalArgumentException("fromIndex(" + fromIndex +
               ") > toIndex(" + toIndex+")");
       if (fromIndex < 0) 
          throw new ArrayIndexOutOfBoundsException(fromIndex);
       if (toIndex > arrayLen) 
          throw new ArrayIndexOutOfBoundsException(toIndex);
    }

On a more serious note, I really wonder where the line is drawn for copyright.  I see a lot of people claiming that AI is producing code they've written verbatim, but sometimes I wonder if everyone just writes certain things the same way.  For the above rangeCheck function, there isn't much opportunity for the individual programmer to be creative.  Perhaps there is a matter of taste on what exceptions you throw, or in what order.  But the chosen ones are certainly what most people think of first, and the order to validate arguments, then check the low value, then check the high value, is pretty much what anyone would do.  Perhaps you could format the error message differently.  That's about it.  So when someone "rips off" your code wholesale, it's could just be that everyone writing that function would have typed in the exact same bytes as you.  You know your style guide is working when you look at code, think you wrote it, but actually you didn't!