public function setImageType($mimeType) {
        if (!in_array($mimeType, [self::SAME_AS_ORIGINAL, self::GIF, self::PNG, self::JPEG, self::SVG], true)) {
            throw new \InvalidArgumentException("\$mimeType '{$mimeType}' is not supported");
        }
        $this->alterImageType = $mimeType;
        return $this;
    }