Laravel 5 Image Intervention Trim Function Not Working

I'm developing card scan project so my users will upload their cards' photo and i will handle these photos to make these better with like trimming. For now i'm trying to do this with image intervention library. I used some function from this library like blur etc. and they're working except trim function. I've checked this http://ift.tt/2dHiJ3h and tried that solution that's not worked me. (Actually i couldn't find the test file which is mentioned in the solution.) By the way i'm suspicious about i've installed that library uncorrectly. If that happened how can i learn it?Finally this is my code;

Image::make(public_path('folder/aa.jpg'))->trim()->save(public_path('scan_card/cc.jpg'));

via Chebli Mohamed