code: public <T> Mapping<T> getMapping(Class<T> clazz) {
          return (cache != null) ? cache.getMapping(clazz, annotationSet)
                  : new Mapping<T>(clazz, annotationSet);
      }
docs: Return the mapping instance for the given class
  
  @param clazz
  the class
  @return mapping instance (new or from cache)