@Nullable
  public OverridingStatus getOverridingStatus() {
    if (myOverridingStatus.getLock().tryLock()) {
      try {
        return !myOverridingStatus.isEmpty()? myOverridingStatus : null;
      }
      finally {
        myOverridingStatus.getLock().unlock();
      }
    }
    return null;
  }
@Nullable
  public OverridingStatus getOverridingStatus()