MongoDB c#更新.PushWrapped，如何使用它

如何在数组中推送一个项目?我看到我只能插入基本值(String, Int32, Int64, Boolean)，但我不能插入一个自定义类的实例到数组中。

//in this way, it work:
var myPlayer = new i_Player();
this.mongo_collection.FindAndModify(
Query.EQ("_id",ID),
SortBy.Ascending("_id"),
Update.PushWrapped<i_Player>("_player", myPlayer),
true
);
// in this way, don't work because i_Player is not an BsonValue but is my CLASS!
var myPlayer = new i_Player();
this.mongo_collection.FindAndModify(
Query.EQ("_id",ID),
SortBy.Ascending("_id"),
Update.Push("_player", myPlayer),
true
);

Update.PushWrapped<i_Player>("_player", myPlayer);

Update.Push("_player", myPlayer.ToBsonDocument());