code: @Override
      public RealJsonEngine newAnotherEngine(OptionalThing<JsonMappingOption> mappingOption) {
          assertArgumentNotNull("mappingOption", mappingOption);
          final JsonEngineResource resource = new JsonEngineResource();
          mappingOption.ifPresent(op -> {
              resource.acceptMappingOption(op);
          });
          return newRuledEngine(resource);
      }
docs: ================