private void CommitSequentialAdd() { if (_state == RobustInserterState.SequentialAdd) { if (_headIndex > 0) { Collection.RemoveRange(0, _headIndex); _headIndex = 0; } if (_sequentialCount < Collection.Count) { Collection.RemoveRange(_sequentialCount, Collection.Count - _sequentialCount); } _state = RobustInserterState.RandomAdd; } }