Submit handler #3 for the chained form.
function batch_test_chained_form_submit_3($form, &$form_state) {
batch_test_stack('submit handler 3');
batch_test_stack('value = ' . $form_state['values']['value']);
$form_state['values']['value']++;
// This redirect should not be taken into account.
$form_state['redirect'] = 'should/be/discarded';
}