AsserEquals not found in WebTestCase Symfony

I have a WebTestCase class:

use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
use Symfony\Bundle\FrameworkBundle\Client;

class ApiAdminInvoiceControllerTest extends WebTestCase
{
    public function test()
    {
        ...
        $this->assertArrayHasKey('id', $array);
        ...
    }
}

I have this error in all asserts:Method 'assertArrayHasKey' not found.