def add_dxf_data(self):
      b = self.retrieve_test_building()

      if b:
         self.assertIsNotNone(b)
         floor_mock = MagicMock()
         floor_mock.to_serializable = MagicMock(return_value={ "b_id": "123", "f_id": "-05", "rooms": [] })
         self.dxf_updater.save_floor( b, floor_mock )
         self.validate_single_document(["dxf", "edilizia"])
      else:
         b = Building( {"_id" : self.db_building["dxf"]["l_b_id"] })
         b.attr("dxf", { "floors": self.db_building["dxf"]["floors"] })
         b.save()