Liskov Substitution Principle (LSP).

LiskovSubstitution.php

<?php

$car = new Car();

$driver = new Driver($car);

$driver->go();

class Driver
{
    protected $car;

    public function __construct(Car $car)
    {
        $this->car = $car;
    }

    public function go()
    {
        $this->car->drive();
    }
}

class Car
{
    public function drive()
    {
        // ...Let's go on an adventure!
    }
}

class Tesla extends Car
{
    //
}

class Audi extends Car
{
    //
}