### Question:
SchoolLevelTypeConverter { public String convert(SchoolLevelType schoolLevelType) { if (schoolLevelType == null) { return null; } return SCHOOL_LEVEL_TYPE_MAP.get(schoolLevelType); }  String convert(SchoolLevelType schoolLevelType); List<String> convertAsList(SchoolLevelType schoolLevelType);  }### Answer:
@Test public void testNull() { String result = converter.convert(null); Assert.assertNull("School category should be null", result); }
@Test public void testEmpty() { SchoolLevelType type = SchoolLevelType.wrap(""); String result = converter.convert(type); Assert.assertNull(result); }