<?php
abstract class hey {
	protected function hello() {
		echo 'hello from hey';
	}
}
class lol extends hey {
	protected function hello() {
		echo 'hello from lol';
	}
	public function do_hello() {
		self::hello();
		parent::hello();
	}
}
$lol = new lol();
$lol->do_hello();