docs: private Transformer getTransformer(Class<?> keyClass) {
        Class<? extends Transformer> transformerClass = getTransformerClass(keyClass);
        if (transformerClass != null) {
           try {
              return transformerClass.newInstance();
           } catch (Exception e) {
              log.couldNotInstantiaterTransformerClass(transformerClass, e);
           }
        }
        return null;
     }