private function parseFeatures($issues)
    {
        $features = array();

        foreach ($issues as $issue) {
            $feature = $this->parseFeature($issue);

            if ($feature instanceof FeatureNode) {
                $features[$issue->key] = $feature;
                $timestamp = $this->cacheService->convertToUnixTimestamp($issue->updated);
                $this->cacheService->write($issue->key, $feature, $timestamp);
            }
        }

        return $features;
    }