Интефейсы PHP

<?php

interface Vehicle {
    public function info ();
}

interface Car extends Vehicle {
    public function drive ();
}

interface Plane extends Vehicle {
    public function fly ();
}

class BMW implements Car {
    public function drive(){
        echo 'Brrrrm...';
    }

    public function info () {
        echo '<h1>About BMW</h1>';
    }
}

class SuperCar implements Car, Plane{

    public function info () {
        echo '<p>Short info</p>';
    }

    public function drive () {
        echo '<p>Brrrrmmmm...</p>';
    }

    public function fly () {
        echo '<p>Ready to fly!</p>';
    }
}

$sc = new SuperCar();
$sc->info();
$sc->drive();
$sc->fly();