inheritance.php

<?php

class SomeParent {
  public function test() {
   echo 'parent';  
  }
}

class Element1 extends SomeParent {
  public function test() {
      parent::test();
      $this->test();
  }
}

class Element2 extends Element1 {
  public function test() {
      parent::test();    
  }
}

$el = new Element2();
$el->test();