protected function parseConfigFiles(Finder $files)
    {
        $config = [];
        foreach ($files as $file) {
            // Check if this is part of a Robo package.
            $path = $file->getRealPath();
            if (!file_exists(dirname($path) . '/RoboFile.php')) {
                continue;
            }
            $this->printTaskInfo(sprintf('Parsing config from %s.', $path));
            $contents = file_get_contents($path);
            $this->printTaskDebug(sprintf('Parsing %s', $contents));
            $config += Yaml::parse($contents);
        }
        return $config;
    }