private function createFeatures()
    {
        $timestamp = $this->cacheService->getLatestTimestamp();
        $issues = $this->jiraService->fetchIssues($timestamp);
        $features = $this->parseFeatures($issues);

        $keys = $this->cacheService->getKeys() ?: array();
        foreach ($keys as $key) {
            if (!array_key_exists($key, $features)) {
                $features[$key] = $this->cacheService->read($key);
            }
        }

        return $features;
    }