Exception on loop after agent call #824

    var creativeWriter = AgentsUtils.newCreativeWriter();
    var scorer = AgentsUtils.newStyleScorer();
    var editor = AgentsUtils.newStyleEditor();

    Predicate<AgenticScope> until = s -> s.readState("score", 0).doubleValue() >= 0.8;

    Map<String, Object> input =
            Map.of(
                    "topic", "fantasy",
                    "style", "fantasy",
                    "audience", "young adults");

    Workflow wf = workflow("loopFlow").agent(creativeWriter)
            .loop(until, scorer, editor).build();

    Object result;
    try (WorkflowApplication app = WorkflowApplication.builder().build()) {
      result = app.workflowDefinition(wf).instance(input).start().get().asJavaObject();
    } catch (Exception e) {
      throw new RuntimeException("Workflow execution failed", e);
    }

    System.out.println(result);

Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Optional.isPresent()" because the return value of "io.serverlessworkflow.api.types.func.ForTaskFunction.getForClass()" is null
	at io.serverlessworkflow.impl.executors.func.JavaForExecutorBuilder.collectionFilterObject(JavaForExecutorBuilder.java:70)
	at io.serverlessworkflow.impl.executors.func.JavaForExecutorBuilder.buildCollectionFilter(JavaForExecutorBuilder.java:65)
	at io.serverlessworkflow.impl.executors.ForExecutor$ForExecutorBuilder.<init>(ForExecutor.java:47)
	at io.serverlessworkflow.impl.executors.func.JavaForExecutorBuilder.<init>(JavaForExecutorBuilder.java:37)
	at io.serverlessworkflow.impl.executors.func.JavaTaskExecutorFactory.getTaskExecutor(JavaTaskExecutorFactory.java:30)
	at io.serverlessworkflow.impl.executors.TaskExecutorHelper.createExecutorBuilderList(TaskExecutorHelper.java:93)
	at io.serverlessworkflow.impl.executors.TaskExecutorHelper.createExecutorList(TaskExecutorHelper.java:65)
	at io.serverlessworkflow.impl.WorkflowDefinition.<init>(WorkflowDefinition.java:59)
	at io.serverlessworkflow.impl.WorkflowDefinition.of(WorkflowDefinition.java:69)
	at io.serverlessworkflow.impl.WorkflowDefinition.of(WorkflowDefinition.java:64)
	at io.serverlessworkflow.impl.WorkflowApplication.lambda$workflowDefinition$0(WorkflowApplication.java:257)
	at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1708)
	at io.serverlessworkflow.impl.WorkflowApplication.workflowDefinition(WorkflowApplication.java:256)
	at io.serverlessworkflow.fluent.agentic.langchain4j.WorkflowAgentsIT.loopTest(WorkflowAgentsIT.java:142)
	... 3 more