setting 'overwrite' to true in KeyCertificate::certificate_import_from_pem throws an exception when a cert exists

suppose I am uploading a certificate, foo.crt that already exists on the F5

when I set overwrite to false, I would get 'Would overwrite file' exception as expected

when I set overwrite to true, I get the Exception: 'The requested Certificate File (/Common/foo.crt) already exists in partition Common'

correct me if I'm wrong but doesn't the latter exception defeats the purpose that is implied in 'overwrite'