@Test
public void testArray() {

    List<Object> list = new LinkedList<>();
    Map<String, Object> map = new HashMap<>();
    map.put("externalId", "[{\"taskRefName\":\"t001\",\"workflowId\":\"w002\"}]");
    map.put("name", "conductor");
    map.put("version", 2);
    list.add(map);
    //noinspection unchecked
    map = (Map<String, Object>) list.get(0);
    assertTrue(map.get("externalId") instanceof String);
    int before = list.size();
    jsonUtils.expand(list);
    assertEquals(before, list.size());
    //noinspection unchecked
    map = (Map<String, Object>) list.get(0);
    assertTrue(map.get("externalId") instanceof ArrayList);
}