The Toolkit class is made available as a service under the name 'ToolkitApi\Toolkit'. Thus in order to use the toolkit within a class you'll need to use a factory to inject it as a dependency like so:
<?php
namespace MyNamespace\Factory;
use Interop\Container\ContainerInterface;
use MyNamespace\MyClassController;
use Zend\ServiceManager\Factory\FactoryInterface;
class MyClassFactory implements FactoryInterface
{
public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
{
return new MyClass(
$container->get(Toolkit::class) // Equivalent of $container->get('\ToolkitApi\Toolkit');
);
}
}