code: private void buildForward(List<List<Vertex>> adjacencyList,
                                LinkedList<X509Certificate> certPathList,
                                boolean searchAllCertStores)
          throws GeneralSecurityException, IOException
      {
          if (debug != null) {
              debug.println("SunCertPathBuilder.buildForward()...");
          }
  
          /* Initialize current state */
          ForwardState currentState = new ForwardState();
          currentState.initState(buildParams.certPathCheckers());
  
          /* Initialize adjacency list */
          adjacencyList.clear();
          adjacencyList.add(new LinkedList<Vertex>());
  
          currentState.untrustedChecker = new UntrustedChecker();
  
          depthFirstSearchForward(buildParams.targetSubject(), currentState,
                                  new ForwardBuilder(buildParams,
                                                     searchAllCertStores),
                                  adjacencyList, certPathList);
      }
docs: /*
  Private build forward method.