public function locateFiles(array $bundles, string $environment): array
    {
        $fixtureFiles = array_flip($this->fixtureLocator->locateFiles($bundles, $environment));
        $fixtureFiles = $fixtureFiles + array_flip($this->fixtureLocator->locateFiles($bundles, ''));

        return array_keys($fixtureFiles);
    }