public override IEnumerable <IXmlChange> Changes(XmlModel model) { var vsXmlModel = model as VSXmlModel; Debug.Assert(vsXmlModel != null); if (vsXmlModel != null) { var internalModel = vsXmlModel.XmlModel; foreach (var modelChange in _editorTransaction.Changes(internalModel)) { yield return(GetXmlChange(modelChange)); } } }