code: public Enumeration<JarEntry> entries2(final JarFile jar, Enumeration e) {
          final Map map = new HashMap();
          map.putAll(signerMap());
          final Enumeration enum_ = e;
          return new Enumeration<JarEntry>() {
  
              Enumeration signers = null;
              JarEntry entry;
  
              public boolean hasMoreElements() {
                  if (entry != null) {
                      return true;
                  }
                  while (enum_.hasMoreElements()) {
                      ZipEntry ze = (ZipEntry) enum_.nextElement();
                      if (JarVerifier.isSigningRelated(ze.getName())) {
                          continue;
                      }
                      entry = jar.newEntry(ze);
                      return true;
                  }
                  if (signers == null) {
                      signers = Collections.enumeration(map.keySet());
                  }
                  while (signers.hasMoreElements()) {
                      String name = (String) signers.nextElement();
                      entry = jar.newEntry(new ZipEntry(name));
                      return true;
                  }
  
                  // Any map entries left?
                  return false;
              }
  
              public JarEntry nextElement() {
                  if (hasMoreElements()) {
                      JarEntry je = entry;
                      map.remove(je.getName());
                      entry = null;
                      return je;
                  }
                  throw new NoSuchElementException();
              }
          };
      }
docs: /*
  Like entries() but screens out internal JAR mechanism entries
  and includes signed entries with no ZIP data.