code: static Method getStartFinalizer(Class<?> finalizer) {
      try {
        return finalizer.getMethod(
            "startFinalizer", Class.class, ReferenceQueue.class, PhantomReference.class);
      } catch (NoSuchMethodException e) {
        throw new AssertionError(e);
      }
    }
docs: Looks up Finalizer.startFinalizer().