final IMapSelection selection = modeController.getController().getSelection();
NodeModel selected = selection.getSelected();
final NodeModel parentNode = selected.getParentNode();
final boolean isLeft = selected.isLeft();
final NodeModel newNode = addNewNode(parentNode, end+1, isLeft);
final SummaryNode summary = modeController.getExtension(SummaryNode.class);
summary.undoableActivateHook(newNode, summary);
final FirstGroupNode firstGroup = modeController.getExtension(FirstGroupNode.class);
final NodeModel firstNode = parentNode.getChildAt(start);
firstGroup.undoableActivateHook(firstNode, firstGroup);
int level = summaryLevel;
for(int i = start+1; i < end; i++){