@Override public List<String> getInvalidityInfo() { // id is allowed to be null when the student is not registered Assumption.assertTrue(team != null); Assumption.assertTrue(comments != null); FieldValidator validator = new FieldValidator(); List<String> errors = new ArrayList<String>(); String error; if (isRegistered()) { error = validator.getInvalidityInfoForGoogleId(googleId); if (!error.isEmpty()) { errors.add(error); } } error = validator.getInvalidityInfoForCourseId(course); if (!error.isEmpty()) { errors.add(error); } error = validator.getInvalidityInfoForEmail(email); if (!error.isEmpty()) { errors.add(error); } error = validator.getInvalidityInfoForTeamName(team); if (!error.isEmpty()) { errors.add(error); } error = validator.getInvalidityInfoForSectionName(section); if (!error.isEmpty()) { errors.add(error); } error = validator.getInvalidityInfoForStudentRoleComments(comments); if (!error.isEmpty()) { errors.add(error); } error = validator.getInvalidityInfoForPersonName(name); if (!error.isEmpty()) { errors.add(error); } return errors; }