public void buildCustomMultiReleaseJar(
     String filename, String multiReleaseValue, Map<String, String> extraAttributes)
     throws IOException {
   JarBuilder jb = new JarBuilder(filename);
   extraAttributes.entrySet().forEach(entry -> jb.addAttribute(entry.getKey(), entry.getValue()));
   jb.addAttribute("Multi-Release", multiReleaseValue);
   jb.build();
 }
 private JarBuilder customMultiReleaseJar(String filename, String multiReleaseValue)
     throws IOException {
   JarBuilder jb = new JarBuilder(filename);
   jb.addAttribute("Multi-Release", multiReleaseValue);
   return jb;
 }