@FunctionName("Parallel")
    public List<String> parallelOrchestratorSad(
            @DurableOrchestrationTrigger(name = "ctx") TaskOrchestrationContext ctx,
            ExecutionContext context) {
        try {
            List<Task<String>> tasks = new ArrayList<>();
            RetryPolicy policy = new RetryPolicy(2, Duration.ofSeconds(15));
            TaskOptions options = new TaskOptions(policy);
            tasks.add(ctx.callActivity("AppendSad", "Input1", options, String.class));
            tasks.add(ctx.callActivity("AppendHappy", "Input2", options, String.class));
            return ctx.allOf(tasks).await();
        } catch (CompositeTaskFailedException e) {
            // Nothing will be caught for this type of exception. 
            for (Exception exception : e.getExceptions()) {
                if (exception instanceof TaskFailedException) {
                    TaskFailedException taskFailedException = (TaskFailedException) exception;
                    System.out.println("Task: " + taskFailedException.getTaskName() + " Failed for cause: " + taskFailedException.getErrorDetails().getErrorMessage());
                }
            }
        }
        return null;
    }
    
    @FunctionName("AppendHappy")
    public String appendHappy(
            @DurableActivityTrigger(name = "name") String name,
            final ExecutionContext context) {
        context.getLogger().info("AppendHappy: " + name);
        return name + "-test-happy";
    }
    
    @FunctionName("AppendSad")
    public String appendSad(
            @DurableActivityTrigger(name = "name") String name,
            final ExecutionContext context) {
        context.getLogger().info("Throw Test Exception: " + name);
        throw new NullPointerException("Test kaibocai exception");
    }