Ulozeni do pole podle atributu v retezeni metod

<?php
interface Metody {
    function set_jmeno($jmeno);
}

abstract class Globalni implements Metody {
    public function set_jmeno($jmeno) {
        $this->jmeno = $jmeno;
    }
}

class Odberatel extends Globalni {
    public $jmeno;
    public $prijmeni;
    public $email;
}
class Dodavatel extends Globalni {
    public $jmeno;
    public $prijmeni;
    public $email;
}



class Test {
    public function __construct() {
        $this->odberatel = new Odberatel;
        $this->dodavatel = new Dodavatel;
    }
}

$test = new Test;
$test->odberatel->set_jmeno("Karlik");
$test->dodavatel->set_jmeno("Tomasek");