public synchronized void authConnection(MemcachedConnection conn,
      OperationFactory opFact, AuthDescriptor authDescriptor,
      MemcachedNode node) {
    interruptOldAuth(node);
    AuthThread newSASLAuthenticator =
        new AuthThread(conn, opFact, authDescriptor, node);
    nodeMap.put(node, newSASLAuthenticator);
  }
Authenticate a new connection. This is typically used by a MemcachedNode in
order to authenticate a connection right after it has been established.

If an old, but not yet completed authentication exists this will stop it in
order to create a new authentication attempt.

@param conn
@param opFact
@param authDescriptor
@param node
src/main/java/net/spy/memcached/auth/AuthThreadMonitor.java