assertNotNull("json shouldn't be null", json);
assertNotSame("json shouldn't be empty", "", json);
FormRepresentation form = decoder.decode(json);
assertNotNull("form shouldn't be null", form);
String json2 = encoder.encode(form);
FormRepresentation form2 = decoder.decode(json2);
assertNotNull("json2 shouldn't be null", json2);
assertNotSame("json2 shouldn't be empty", "", json2);