Nette\DI\ServiceDefinition::setClass PHP Method

    public function setClass($class, array $args = [])
    {
        call_user_func($this->notifier);
        $this->class = $class ? ltrim($class, '\\') : NULL;
        if ($args) {
            $this->setFactory($class, $args);
        }
        return $this;
    }

 function getAssets()
 {
     $serviceDefinition = new ServiceDefinition();
     $serviceDefinition->setClass('Mike227\\NAssetic\\AssetCollection');
     $serviceDefinition->setArguments(array(array('test6.js'), array(new TestFilter('#FILTER')), __DIR__ . '/../sources/'));
     return array('js1' => new GlobAsset(__DIR__ . '/../sources/test1.*'), 'js2' => array(new GlobAsset(__DIR__ . '/../sources/test2.*'), __DIR__ . '/../sources/test3.js', array(__DIR__ . '/../sources/test4.js', new GlobAsset(__DIR__ . '/../sources/test5.*')), 'serviceDef' => $serviceDefinition));
 }