private void UpdatePrevAndNextLinks(IInstruction value) { if (value == null) return; var prevIndex = this.Index - 1; if (prevIndex >= 0) { var prev = _instructions[prevIndex]; if (prev != null) prev.SetNext(value); } var nextIndex = Index + 1; if (nextIndex >= _instructions.Count) return; var next = _instructions[nextIndex]; if (next != null) value.SetNext(next); }