Cd_graph {

{{
 HashSet definedClasses = new HashSet();   // Collection of defined classes

 // These collections will prevent duplicate error messages from being displayed
 HashSet undefinedClasses = new HashSet(); // Collection of undefined classes
 HashSet duplicateDefined = new HashSet(); // Collection of classes defined more than once

 public void findDefinedClasses(final ClassGraph cg) {
    /*
	 Traverse to all defined classes and create a 
    	  hashset of defined classes
    */
    Strategy sg = new Strategy("from Cd_graph bypassing Neighbors to Vertex");
    
    definedClasses = (HashSet) 
    cg.traverse( this, sg, new Visitor() {
      HashSet h;
      public void start(){h = new HashSet();}

      public void before( Vertex host ) { 
	Ident vname = host.get_vertex_name();
	
	if (h.contains(vname)) {// Check for multiple definitions
	  if(!duplicateDefined.contains(vname))
		System.out.println(" *** ERROR: Class " + vname + 
		" is defined more than once in the class dictionary.");
	  duplicateDefined.add(vname);
	} else { 
	  // Add to the hashSet of defined classes
	  h.add(vname);
	}
      }
      public Object getReturnValue(){return h;}	
    }); // End traversal

 }// End function

}}
}