code: public ExtensionAuthor getExtensionAuthor(String name, String url)
      {
          return getExtensionAuthor(new DefaultExtensionAuthor(name, url));
      }
docs: Store and return a weak reference equals to the passed {@link ExtensionAuthor}.
  
  @param name the name of the author
  @param url the url of the author public profile
  @return unique instance of {@link ExtensionAuthor} equals to the passed one