// then
assertEquals(0, activity.getListeners().size());
HumanTaskActivityBehavior behavior = (HumanTaskActivityBehavior) activity.getActivityBehavior();
TaskDefinition taskDefinition = behavior.getTaskDefinition();
assertNotNull(taskDefinition);
assertEquals(1, taskDefinition.getTaskListeners().size());
List<TaskListener> createListeners = taskDefinition.getTaskListener(event);
assertEquals(1, createListeners.size());
TaskListener listener = createListeners.get(0);
assertTrue(listener instanceof DelegateExpressionTaskListener);