/**
* Asynchronously sends a message to multiple servers, potentially multiple times, registering a
* listener to receive a callback on success or exception. Multiple asynchronous lookups can be
* performed in parallel. Since the callback may be invoked before the function returns, external
* synchronization is necessary.
*
* @param query The query to send
* @param listener The object containing the callbacks.
* @return An identifier, which is also a parameter in the callback
*/
public Object sendAsync(final Message query, final ResolverListener listener) {
Resolution res = new Resolution(this, query);
res.startAsync(listener);
return res;
}
