public function testExtendReturnsDefinitionForModificationWhenCalledWithAValidService()
{
$c = new Container();
$definition = $c->add('service', 'OrnoTest\\Assets\\Baz');
$extend = $c->extend('service');
$this->assertInstanceOf('Orno\\Di\\Definition\\DefinitionInterface', $extend);
$this->assertSame($definition, $extend);
}