NetClass append(String p_name,board.BrdLayerStructure p_layer_structure,ClearanceMatrix p_clearance_matrix){
  NetClass new_class=new NetClass(p_name,p_layer_structure,p_clearance_matrix);
  class_list.add(new_class);
  return new_class;
}

NetClass append ( String p_name , board . BrdLayerStructure p_layer_structure , ClearanceMatrix p_clearance_matrix ) { NetClass new_class = new NetClass ( p_name , p_layer_structure , p_clearance_matrix ) ; class_list . add ( new_class ) ; return new_class ; }
appends a new empty class with name p_name to the class array
