How to show confidence attribute wit Naive Bayes operator

Hi to everyone,
I have a little problem, I'm trying to implement the learner operator Naive Bayes using the rapid miner API (in java using Net Beans). My code is:
       
      MemoryExampleTable table = new MemoryExampleTable(attributes);
        table.addDataRow(new DoubleArrayDataRow(context));

        IOContainer container = new IOContainer(new IOObject[]{table.createExampleSet(label)});
        container = container.append(model);

        Operator applier = OperatorService.createOperator(ModelApplier.class);
        container = applier.apply(container);

        ExampleSet result = container.get(ExampleSet.class);
       
        Attribute predictedLabel = result.getAttributes().getPredictedLabel();
        double prediction = Double.parseDouble(result.iterator().next().getNominalValue(predictedLabel));

I'm trying to show the confidence attribute of the prediction but I don't know how to do it, I implemented this code:
       
        double values[] = new double [100];
        Iterator<Attribute> it = result.getAttributes().allAttributes();
        int i = 0;
while(it.hasNext()) {
            Example e = result.getExample(0);
            values = e.getValue(it.next());
            i++;
            System.out.println(values);
}
but the output is all zeros;

Anyone know how can I take information about the confidence attribute? I tried also this method:
Attribute confidence = result.getAttributes().getSpecial("confidence(0)");
but the result is null.

Thank you for your help.