### Question:
JsonUtils { public static String renderAsJsonString(Map<String, Object> map) { String json = null; ObjectMapper mapper = new ObjectMapper(); try { json = mapper.writeValueAsString(map); } catch ( JsonProcessingException e ) { LOG.failedToSerializeMapToJSON( map, e ); } return json; }  static String renderAsJsonString(Map<String, Object> map); static String renderAsJsonString(Object obj); static String renderAsJsonString(Object obj, FilterProvider filterProvider, DateFormat dateFormat); static Object getObjectFromJsonString(String json); static Map<String, String> getMapFromJsonString(String json); static Map<String,HashMap<String, ArrayList<HashMap<String, String>>>> getFileStatusesAsMap(String json);  }### Answer:
@Test public void testRenderAsJson() { Map<String, Object> map = new HashMap<>(); map.put("access_token", "ksdfh3489tyiodhfjk"); map.put("token_type", "Bearer"); map.put( "expires_in", "1364487943100" ); String result = JsonUtils.renderAsJsonString(map); assertThat( result, containsString( expiresIn ) ); assertThat( result, containsString( tokenType ) ); assertThat( result, containsString( accessToken ) ); }