网上有些文章给的示例直接传bson.D，可能是客户端版本问题，在mongo-go-driver@v2.0.0上Find方法要求传入type M map[string]interface{}，直接传bson.D会报如下错误：
“cannot transform type bson.D to a BSON Document: WriteArray can only write a Array while positioned on a Element or Value but is positioned on a TopLevel”
//报错：cannot transform type bson.D to a BSON Document: WriteArray can only write a Array while positioned on a Element or Value but is positioned on a TopLevel
cur, err := collection.Find(ctx, bson.D{{"type", "电视剧"}})
//正确
cur, err := collection.Find(ctx, bson.D{{"type", "电视剧"}}.Map())
//正确
cur, err := collection.Find(ctx, bson.M{"type":"电视剧"})