JSONUtil { public String readMapToString(Map<?, ?> map) { try { return JsonUtilsV2.mapToJson(map); } catch (Exception e) { throw restErrorUtil.createRESTException( "Invalid input data: " + e.getMessage(), MessageEnums.INVALID_INPUT_DATA); } }  File writeJsonToFile(ViewBaseBean viewBean, String fileName); Map<String, String> jsonToMap(String jsonStr); String readMapToString(Map<?, ?> map); String readListToString(List<?> list); String writeObjectAsString(Serializable obj); T writeJsonToJavaObject(String json, Class<T> tClass);  }
@Test public void testReadMapToString() { Map<?, ?> map = new HashMap<Object, Object>(); String value = jsonUtil.readMapToString(map); Assert.assertNotNull(value); }