static class JavaXClassLoaderWithParent2 extends JavaXClassLoader {
  ClassLoader virtualParent;
  L<S> classesToSkip; // classes that should be taken from parent

  *(S progID, L<File> files, ClassLoader virtualParent, L<S> classesToSkip) {
    super(progID, files);
    this.virtualParent = virtualParent;
    this.classesToSkip = classesToSkip;
  }
  
  protected Class<?> findClass(S name) throws ClassNotFoundException {
    if (shouldDelegate(name)) {
      Class<?> c = virtualParent.loadClass(name);
      if (c != null) ret c;
    }
    ret super.findClass(name);
  }
    
  bool shouldDelegate(S name) {
    for (S s : classesToSkip)
      if (eq(name, s) || startsWith(name, s + "$"))
        true;
    false;
  }
}

Began life as a copy of #1010568