code: @Override
      public Collection<URL> getURLs() {
          try {
              // As a container URL, the URL must end with a trailing slash.
              URL entryUrl = rootContainer.createEntryUri( getRelativePath() + "/" ).toURL();
              return Collections.singleton(entryUrl);
          } catch ( MalformedURLException e ) {
              // FFDC
              return Collections.emptyList();
          }
      }
docs: Answer the URLs of this entry.  See {@link ZipFileContainer#createEntryUri}
  for details.
  
  Answer a singleton, unless the archive and entry values cause a malformed
  URL to be created. If a malformed URL is created, answer an empty collection.
  
  @return The collection of URLs of this entry.