static class JavaXClassLoaderWithParents extends JavaXClassLoaderWithParent {
  // keys: full class names or package names
  // (inner classes are automatically included)
  NavigableMap<S, ClassLoader> parentMap = syncTreeMap();
  
  *(S progID, L<File> files, ClassLoader virtualParent) {
    super(progID, files, virtualParent);
  }

  *(S progID, L<File> files) {
    super(progID, files, null);
  }
  
  protected Class<?> findClass(S name) throws ClassNotFoundException {
    ClassLoader parent = findParentForClass(name);
    if (parent != null)
      ret parent.loadClass(name);
    else
      ret super.findClass(name);
  }
    
  ClassLoader findParentForClass(S name) {
    ClassLoader cl = parentMap.get(name);
    if (cl != null) ret cl;
    S s = parentMap.floorKey(name);
    if (startsWithOneOf(name, s + "$", s + "."))
      ret parentMap.get(s);
    null;
  }
  
  void addParent(S name, ClassLoader loader) {
    parentMap.put(name, loader);
  }
}

Began life as a copy of #1011216