@Override
            public String getFieldName(int number)
            {
                switch (number)
                {
                    case 1:
                        return "n";
                    case 2:
                        return "d";
                    default:
                        return null;
                }
            }
Testing for xml ser/deser against messages.

@author David Yu
@created May 24, 2010
protostuff-xml/src/test/java/io/protostuff/XmlCoreSerDeserTest.java