gistfile1.php

<? 

abstract class AbstractParent {

	function __construct($param) { print_r($param); }

        public static function test() { return new self(1234); }


}

class SpecificClass extends AbstractParent {}

SpecificClass::test();

?>

gistfile2.txt

$ php test.php 

Fatal error: Cannot instantiate abstract class AbstractParent in test.php on line 8