BaseApiControllerTestCase.php

<?php

//...

namespace Tests\ApiBundle\TestCase;

//...
use Liip\FunctionalTestBundle\Test\WebTestCase as WebTestCase;
//...

abstract class BaseApiControllerTestCase extends WebTestCase
{
      //...
      public function tearDown()
      {
            if ($this->em instanceof EntityManager) {
                  $this->em->close();
            }
            $this->em = null;

            $refl = new \ReflectionObject($this);
            foreach ($refl->getProperties() as $prop) {
                  if (!$prop->isStatic() && 0 !== strpos($prop->getDeclaringClass()->getName(), 'PHPUnit_')) {
                        $prop->setAccessible(true);
                        $prop->setValue($this, null);
                  }
            }
            unset($refl);

            \gc_collect_cycles();

            parent::tearDown();
    }
}