source: class TestJsonUtils {
  
      private JsonUtils jsonUtils;
  
      @Test
      public void testMap() {
  
target:         Map<String, Object> map = new HashMap<>();
          map.put("externalId", "{\"taskRefName\":\"t001\",\"workflowId\":\"w002\"}");
          map.put("name", "conductor");
          map.put("version", 2);
  
          assertTrue(map.get("externalId") instanceof String);
  
          jsonUtils.expand(map);
  
          assertTrue(map.get("externalId") instanceof LinkedHashMap);
      }
  
  }