public static Set<TaskModel> generateTaskModels(int[] partitions) {
    Set<TaskModel> models = new HashSet<>(partitions.length);
    for (int partition : partitions) {
      models.add(getTaskModel(partition));
    }
    return models;
  }
Note: This is artificial. It makes assumptions about task grouping, changelog partition mapping, etc.
that will likely not be true at runtime, but are not the focus of this test.
samza-core/src/test/java/org/apache/samza/container/mock/ContainerMocks.java