public boolean isEmpty() {
    synchronized (myLock) {
      for (Map.Entry<ErrorTreeElementKind, List<ErrorTreeElement>> entry : mySimpleMessages.entrySet()) {
        final List<ErrorTreeElement> elements = entry.getValue();
        if (elements != null && !elements.isEmpty()) {
          return false;
        }
      }
    }
    return true;
  }
public boolean isEmpty()