wro4j-core/src/main/java/ro/isdc/wro/model/factory/DefaultWroModelFactoryDecorator.java
public static WroModelFactory decorate(final WroModelFactory decorated,
      final List<Transformer<WroModel>> modelTransformers) {
    return decorated instanceof DefaultWroModelFactoryDecorator ? decorated : new DefaultWroModelFactoryDecorator(
        decorated, modelTransformers);
  }
public static WroModelFactory decorate(final WroModelFactory decorated,
      final List<Transformer<WroModel>> modelTransformers) {
    return decorated instanceof DefaultWroModelFactoryDecorator ? decorated : new DefaultWroModelFactoryDecorator(
        decorated, modelTransformers);
  }
Factory method which takes care of redundant decoration.