public function testOneToOneKey()
{
$place = new Place();
$place->name = 'Derry';
$place->save();
$restaurant = new Restaurant();
$restaurant->name = 'Burger mix';
$restaurant->place = $place;
$restaurant->save();
$this->assertEquals(1, Restaurant::objects()->filter(['place' => $place->id])->count());
$this->assertEquals(1, $place->restaurant->pk);
$restaurant->delete();
$this->assertNull($place->restaurant);
}
