public function &getTaggableObjectData(ITaggable $object, array &$taggableObjectData)
 {
     if (!$object instanceof IFile) {
         throw new EyeInvalidClassException('$object must be an instance of IFile.');
     }
     if (!$object->exists()) {
         throw new EyeFileNotFoundException('Unable to tag non-existing file ' . $object->getPath() . '.');
     }
     $taggableObjectData[self::OBJECTDATA_KEY_PATH] = $object->getPath();
     return $taggableObjectData;
 }