// internal methods
 internal override void WriteBodyTo(BsonStreamWriter streamWriter)
 {
     streamWriter.WriteInt32(_cursorIds.Length);
     foreach (long cursorId in _cursorIds)
     {
         streamWriter.WriteInt64(cursorId);
     }
 }
 // internal methods
 internal override void WriteBodyTo(BsonStreamWriter streamWriter)
 {
     streamWriter.WriteInt64(_cursorId);
 }