$ci = Rougin\SparkPlug\Instance::create();

// You can now use its instance
$ci->load->helper('inflector');

class SparkPlugTest extends \PHPUnit_Framework_TestCase
{
    /**
     * Checks if the CodeIgniter instance is successfully retrieved.
     * 
     * @return void
     */
    public function testCodeIgniterInstance()
    {
        // Path of your test application
        $appPath = __DIR__ . '/TestApp';

        // Instance::create($appPath, $_SERVER, $GLOBALS)
        $ci = \Rougin\SparkPlug\Instance::create($appPath);

        $this->assertInstanceOf('CI_Controller', $ci);
    }
}