@Override
  public boolean addObserver(ConnectionObserver obs) {
    boolean rv = mconn.addObserver(obs);
    if (rv) {
      for (MemcachedNode node : mconn.getLocator().getAll()) {
        if (node.isActive()) {
          obs.connectionEstablished(node.getSocketAddress(), -1);
        }
      }
    }
    return rv;
  }
Add a connection observer.

If connections are already established, your observer will be called with
the address and -1.

@param obs the ConnectionObserver you wish to add
@return true if the observer was added.
src/main/java/net/spy/memcached/MemcachedClient.java