public function testIsIterable()
{
$property1 = new Property('username', 'alice');
$property2 = new Property('owner', 'bob');
$bag = (new PropertyBag())->with($property1)->with($property2);
$array = [];
foreach ($bag as $index => $property) {
$array[$index] = $property;
}
$this->assertSame([$property1, $property2], $array);
}