public function getRequiredFiles($config)
    {
        $files = [];
        
        foreach ($config as $key => $name) {
            
            if (is_numeric($key) && is_string($name)) {
                
                $files[] = $name;
                
            } elseif (is_numeric($key) && is_array($name)) {
                
                foreach ($name as $module => $file) {
                    $files[] = sprintf('%s: %s', $module, $file);
                }
                
            } elseif (!is_numeric($key) && is_array($name)) {
                
                foreach ($name as $file) {
                    $files[] = sprintf('%s: %s', $key, $file);
                }
                
            }
            
        }
        
        return $files;
    }