class NetworkTopologyImpl implements NetworkTopology {

  public int getNumOfLeafNode(String loc) {
    netlock.readLock().lock();
    try {
      Node node = getNode(loc);
      if (node != null) {
        return node.getNumOfLeaves();
      }
    } finally {
      netlock.readLock().unlock();
    }
    return 0;
  }

  public  NetworkTopologyImpl(ConfigurationSource conf);
  @VisibleForTesting public  NetworkTopologyImpl(NodeSchemaManager manager);

}