The Notify interface defines a modified() method used by the GraphPanel class to notify the NetWorKsPanel class of changes to the graph. The Parse class contains methods useful in parsing String objects. The Sort class contains a heap sort capable of sorting arrays of objects which implement the Sortable interface. Note that the Vertex and Edge classes implement Sortable. The Sortable interface defines a precedes() method used by the Sort methods. The Trash class implements a graphic selectable trash can. The UNNL class implements a unused natural number list used by the GraphPanel class to assign numbers to vertices. The xPoint class adds vector-like functionality to the Java library Point class.