protected void Invoke(Address addr)
{
Channel q = new Channel(1);
q.CloseEvent += delegate(object send, EventArgs ea) {
RpcResult result = null;
if(q.Count > 0) {
result = q.Dequeue() as RpcResult;
}
ProcessResults(addr, result);
};
AHSender sender = new AHGreedySender(_node, addr);
_node.Rpc.Invoke(sender, q, "sys:link.GetNeighbors");
}