public static extern int zoo_awget(IntPtr zh, string path,
watcher_fn watcher, IntPtr watcherCtx,
data_completion_t completion, IntPtr data);
public static extern int zoo_awget_children2(IntPtr zh, string path,
watcher_fn watcher, IntPtr watcherCtx,
strings_stat_completion_t completion,
IntPtr data);
public static extern IntPtr zookeeper_init(string host, watcher_fn fn,
int recv_timeout, IntPtr clientid, string context, int flags);