private void processAction(IDocument document, int selectionStartLine, int selectionEndLine) {
IStructuredModel model = StructuredModelManager.getModelManager().getExistingModelForEdit(document);
if (model != null) {
try {
model.beginRecording(this, XMLUIMessages.ToggleComment_tooltip);
model.aboutToChangeModel();
for (int i = selectionStartLine; i <= selectionEndLine; i++) {
try {
if (document.getLineLength(i) > 0) {
if (isCommentLine(document, i)) {