code: boolean belongsToCluster(final MemcachedNode node) {
      for (MemcachedNode n : locator.getAll()) {
        if (n.getSocketAddress().equals(node.getSocketAddress())) {
          return true;
        }
      }
      return false;
    }
docs: Makes sure that the given node belongs to the current cluster.
  
  Before trying to connect to a node, make sure it actually belongs to the
  currently connected cluster.