*/
private void closeGroup(Node folderNode) {
fireGraphPreEvent();
getEdgeGrouper().handleCloseFolder(folderNode);
AbstractSelectionStrategy preLayoutSelection = new SelectNodeAndItsEdges(this, folderNode);
preLayoutSelection.initSelection();
setPreLayoutSelectionStrategy(preLayoutSelection);
AbstractSelectionStrategy postLayoutSelection = new SelectNode(this, folderNode);
postLayoutSelection.initSelection();
setPostLayoutSelectionStrategy(postLayoutSelection);