lane 1                                                                                                                    lane 2                                                               
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                             some action                                                                                                                                                                         
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                   test 1                                                                                                                                        
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                            dummy node                           
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                                 
                                                                                                                                                                                                           test 2