/// <summary>取消订阅</summary>
/// <param name="user">订阅者</param>
/// <param name="userState">订阅者</param>
/// <returns></returns>
public Boolean Remove(String user, Object userState)
{
//if (!Consumers.Remove(user)) return false;
if (!Consumers.TryGetValue(user, out var cs))
{
return(false);
}
var rs = cs.Remove(userState);
// 如果没有订阅者，则删除消费者
if (rs && cs.Subscribers.IsEmpty)
{
Consumers.Remove(user);
}
return(rs);
}