@POST
 @Path("/class")
 public Response addClass(String json) {
   try {
     ObjectNode clazzJson = (ObjectNode) jsonNodeFromString(json);
     Clazz clazz = LomBusinessFacade.getInstance().addClass(Clazz.clazzFromJson(clazzJson));
     ResponseBuilderImpl builder = new ResponseBuilderImpl();
     builder.status(201);
     builder.entity(clazz.getJson().toString());
     return builder.build();
   } catch (Exception e) {
     return Response.notAcceptable(null).build();
   }
 }
 @POST
 @Produces(MediaType.APPLICATION_JSON)
 @Path("/instance")
 public Response addInstance(String json) {
   try {
     ObjectNode instanceJson = (ObjectNode) jsonNodeFromString(json);
     Instance instance =
         LomBusinessFacade.getInstance().addInstance(Instance.instanceFromJson(instanceJson));
     ResponseBuilderImpl builder = new ResponseBuilderImpl();
     builder.status(201);
     builder.entity(instance.getJson().toString());
     return builder.build();
   } catch (Exception e) {
     return Response.notAcceptable(null).build();
   }
 }
 @POST
 @Path("/class/{fullName}/attributes")
 public Response addAttributeToClass(@PathParam("fullName") String fullName, String json) {
   Clazz clazz = LomBusinessFacade.getInstance().getClass(fullName);
   if (clazz != null) {
     try {
       ObjectNode attributeJson = (ObjectNode) jsonNodeFromString(json);
       Attribute attribute = Attribute.attributeFromJson(attributeJson);
       attribute.setClassID(clazz.getId());
       attribute = LomBusinessFacade.getInstance().addAttribute(attribute);
       ResponseBuilderImpl builder = new ResponseBuilderImpl();
       builder.status(201);
       builder.entity(attribute.getJson().toString());
       return builder.build();
     } catch (Exception e) {
       return Response.notAcceptable(null).build();
     }
   }
   return Response.notAcceptable(null).build();
 }