BsonEmpty
namespace Newtonsoft.Json.Bson
{
    internal class BsonEmpty : BsonToken
    {
        public static readonly BsonToken Null = new BsonEmpty(BsonType.Null);
        public static readonly BsonToken Undefined = new BsonEmpty(BsonType.Undefined);
        public override BsonType Type { get; }
        private BsonEmpty(BsonType type)
        {
            Type = type;
        }
    }
}