/** * Set mime type to all children. * * @param string $mimeType * * @return $this */ public function setAcceptedMimeType($mimeType) { $mimeType = strtolower(trim($mimeType)); self::$acceptedMimeTypes->set($mimeType); $this->walkIn(function (UploadedFile &$file) use($mimeType) { $file->getAcceptedMimeType()->set($mimeType); }); return $this; }