The Set interface

Which programming languages will the set langs1 contain after executing the following code:

Set<String> langs1 = new HashSet<>();

langs1.add("Java");
langs1.add("Scala");
langs1.add("Kotlin");

Set<String> langs2 = new HashSet<>();

langs2.add("Python");
langs2.add("Kotlin");
langs2.add("JAVA");

langs1.addAll(langs2);