public function test_changing_container_changes_invoker()
 {
     $kernel = new Kernel(new Container());
     $invoker = $kernel->getProviderInvoker();
     $container = new Container();
     $kernel->setContainer($container);
     $this->assertTrue($kernel->getProviderInvoker() !== $invoker);
     $this->assertTrue($kernel->getProviderInvoker() instanceof IProviderInvoker);
 }