output: #fixed code
                                  @Override
      public HttpSession getSession(final boolean create) {
          return servletContext.getSession(exchange.getExchange(), create);
      }
input: #vulnerable code 
                                  @Override
      public HttpSession getSession(final boolean create) {
          if (httpSession == null) {
              Session session = exchange.getExchange().getAttachment(Session.ATTACHMENT_KEY);
              if (session != null) {
                  httpSession = new HttpSessionImpl(session, servletContext, servletContext.getDeployment().getApplicationListeners(), exchange.getExchange(), false);
              } else if (create) {
                  final SessionManager sessionManager = exchange.getExchange().getAttachment(SessionManager.ATTACHMENT_KEY);
                  try {
                      Session newSession = sessionManager.getOrCreateSession(exchange.getExchange()).get();
                      httpSession = new HttpSessionImpl(newSession, servletContext, servletContext.getDeployment().getApplicationListeners(), exchange.getExchange(), true);
                      servletContext.getDeployment().getApplicationListeners().sessionCreated(httpSession);
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
          }
          return httpSession;
      } 
                              #location 10 
                              #vulnerability type NULL_DEREFERENCE