internal void Add(OsuBeatmap b)
{
_beatmaps.Add(b);
}
/// <summary>
/// 检测指定谱面是否在列表中
/// </summary>
/// <param name="b">要检测的谱面</param>
/// <returns>布尔值，指示谱面是否在列表中</returns>
public bool Contains(OsuBeatmap b)
{
return(_beatmaps.Contains(b));
}