class Destination{                      class Source{
    @JMap
    private String id;                      private String id;
    @JMap("sourceField")                    
    private String destinationField;        private String sourceField;
    private String other;                   private String other;
    // getters and setters...               // getters and setters...
}                                       }

JMapperAPI jmapperAPI = new JMapperAPI()
    .add(mappedClass(Destination.class)
             .add(attribute("id")
                     .value("id"))
             .add(attribute("destinationField")
                     .value("sourceField")));

JMapper<Destination, Source> mapper;

mapper = new JMapper<>(Destination.class, Source.class);

mapper = new JMapper<>(Destination.class, Source.class, xml);

mapper = new JMapper<>(Destination.class, Source.class, jmapperAPI);

Source source = new Source("id", "sourceField", "other");
Destination destination = mapper.getDestination(source);

destination ["id", "sourceField", null]