/**
  * {@inheritdoc}
  */
 public static function getConfigSchema()
 {
     $rosConfig = new OpenStackConfig();
     $pathConfig = new FilePublicPath();
     $out = null;
     $rosSchema = $rosConfig->getConfigSchema();
     $pathSchema = $pathConfig->getConfigSchema();
     static::updatePathSchema($pathSchema);
     if (!empty($rosSchema)) {
         $out = $rosSchema;
     }
     if (!empty($pathSchema)) {
         $out = $out ? array_merge($out, $pathSchema) : $pathSchema;
     }
     return $out;
 }