Class, interface, or enum expected error in the following code while writing in Android Studio; where are the problems?

Question

I am getting error while debugging the below java code which says "error: class, interface, or enum expected". Where it goes wrong??

 @Override
protected void onStart() {
    super.onStart();
    mAuth.addAuthStateListener(firebaseAuthListener);
}

@Override
protected void onStop() {
    super.onStop();
    mAuth.removeAuthStateListener(firebaseAuthListener);
}