protected function isFixtureAlreadyLoaded($fixtureObject)
    {
        if (!$this->loadedFixtures) {
            $this->loadedFixtures = [];

            $loadedFixtures = $this->em->getRepository('OkvpnFixtureBundle:DataFixture')->findAll();
            /** @var DataFixture $fixture */
            foreach ($loadedFixtures as $fixture) {
                $this->loadedFixtures[$fixture->getClassName()] = $fixture->getVersion() ?: '0.0';
            }
        }

        $alreadyLoaded = false;

        if (isset($this->loadedFixtures[get_class($fixtureObject)])) {
            $alreadyLoaded = true;
            $loadedVersion = $this->loadedFixtures[get_class($fixtureObject)];
            if ($fixtureObject instanceof VersionedFixtureInterface
                && version_compare($loadedVersion, $fixtureObject->getVersion()) == -1
            ) {
                if ($fixtureObject instanceof LoadedFixtureVersionAwareInterface) {
                    $fixtureObject->setLoadedVersion($loadedVersion);
                }
                $alreadyLoaded = false;
            }
        }

        return $alreadyLoaded;
    }