output: #fixed code
                                  private ContainerCreationStatus getContainerCreationStatus (String serviceId, String nodePort) throws DockerException, InterruptedException {
          List<Task> tasks = dockerClient.listTasks();
          for (Task task : tasks) {
              if (task.serviceId().equals(serviceId)) {
                  ContainerStatus containerStatus = task.status().containerStatus();
                  if (containerStatus != null) {
                      String containerId = containerStatus.containerId();
                      String containerName =  containerStatus.containerId();
                      return new ContainerCreationStatus(true, containerName, containerId, nodePort);
                  }
              }
          }
  
          return null;
      }
input: #vulnerable code 
                                  private ContainerCreationStatus getContainerCreationStatus (String serviceId, String nodePort) throws DockerException, InterruptedException {
          List<Task> tasks = dockerClient.listTasks();
          for (Task task : tasks) {
              if (task.serviceId().equals(serviceId)) {
                  ContainerStatus containerStatus = task.status().containerStatus();
                  String containerId = containerStatus.containerId();
                  String containerName =  containerStatus.containerId();
                  return new ContainerCreationStatus(true, containerName, containerId, nodePort);
              }
          }
  
          return null;
      } 
                              #location 6 
                              #vulnerability type NULL_DEREFERENCE