code: @PUT
      @Path("{group}/{id}")
      @Consumes("application/x.json-update-role")
      public SuccessResponse updateRoleFromUpdateRequest(@PathParam("group") String group, @PathParam("id") String id,
                                                         UpdateEmoRoleRequest request, @Authenticated Subject subject) {
          _uac.updateRole(subject, request.setRoleKey(new EmoRoleKey(group, id)));
          return SuccessResponse.instance();
      }
docs: Alternate endpoint for updating a role.  Although not REST compliant it provides a more flexible
  interface for specifying role attributes, such as by supporting partial updates.