* Should be idempotent.
* Returns false if the parameters are unacceptable and the transform should fail
* @param File $image
- * @param array $params
+ * @param array &$params
*/
abstract function normaliseParams( $image, &$params );
*
* @see LocalFile::purgeThumbnails
*
- * @param array $files
+ * @param array &$files
* @param array $options Purge options. Currently will always be
* an array with a single key 'forThumbRefresh' set to true.
*/