### Question:
MapperFieldName extends Mapper<LogFeederProps> { @Override public boolean init(String inputDesc, String fieldName, String mapClassCode, MapFieldDescriptor mapFieldDescriptor) { init(inputDesc, fieldName, mapClassCode); newValue = ((MapFieldNameDescriptor)mapFieldDescriptor).getNewFieldName(); if (StringUtils.isEmpty(newValue)) { LOG.fatal("Map field value is empty."); return false; } return true; }  @Override boolean init(String inputDesc, String fieldName, String mapClassCode, MapFieldDescriptor mapFieldDescriptor); @Override Object apply(Map<String, Object> jsonObj, Object value);  }### Answer:
@Test public void testMapperFieldName_noNewFieldName() { LOG.info("testMapperFieldName_noNewFieldName()"); MapFieldNameDescriptorImpl mapFieldNameDescriptor = new MapFieldNameDescriptorImpl(); MapperFieldName mapperFieldName = new MapperFieldName(); assertFalse("Was able to initialize!", mapperFieldName.init(null, "someField", null, mapFieldNameDescriptor)); }