// initialize
this.tree = tree;
this.parameter = parameter;
this.popup = new JPopupMenu();
this.menuItems = new ArrayList<IMenuItem>(10);
this.openVerticesMenuItem = new OpenVerticesMenuItem(tree, this.parameter.model, this.parameter.userInterface);
this.selectionTabMenuItem = new SelectionTabMenuItem(tree, this.parameter.userInterface);
// check input parameter
if(tree == null) return;
// create items
this.menuItems.add(this.openVerticesMenuItem);