<?php
error_reporting(E_ALL | E_STRICT);

class A
{
	public function signatureTest($groups, $data, $default = null)
	{
		var_dump($default);
	}
	
}

class B extends A
{
	public function signatureTest($groups, $data)
	{
		parent::signatureTest($groups, $data);
	}
}

$b = new B();
$b->signatureTest(array(), 'dummy');

?>