private void updateFinalKeys(Set<EKey> prevKeys) {
    if (myFinalThrowKeys == null) {
      myFinalThrowKeys = new HashSet<>(prevKeys);
    } else {
      if (myFinalThrowKeys.isEmpty()) {
        myThrowKeys = null;
        return;
      }
      myFinalThrowKeys.retainAll(prevKeys);
    }
  }
private void updateFinalKeys(Set<EKey> prevKeys)