/** * Transforms an Image with some resizing information into an ETag. * * @param ImageInterface $image Image * @param string $height Height * @param string $width Width * @param string $type Type of resizing * * @return string ETag generated */ public function transform(ImageInterface $image, $height, $width, $type) { return sha1($image->getId() . '.' . $image->getUpdatedAt()->getTimestamp() . '.' . $height . '.' . $width . '.' . $type); }