The getRandomName() function return wrong file Extension

@sammyskills  this is what i get when i do a var_dump($imageFile) :

Code:

object(CodeIgniter\HTTP\Files\UploadedFile)#78 (10) { ["size":protected]=> int(47156) ["originalMimeType":protected]=> string(9) "image/png" ["path":protected]=> string(24) "C:\xampp\tmp\php3B74.tmp" ["clientPath":protected]=> string(14) "banner-img.png" ["originalName":protected]=> string(14) "banner-img.png" ["name":protected]=> string(14) "banner-img.png" ["error":protected]=> int(0) ["hasMoved":protected]=> bool(false) ["pathName":"SplFileInfo":private]=> string(24) "C:\xampp\tmp\php3B74.tmp" ["fileName":"SplFileInfo":private]=> string(11) "php3B74.tmp" }