my $error;

sub error {
        return $error;
}

sub new{
    my $class = shift;
        my %cfg = (
                machine => '',
                @_
        );

        unless ($cfg{machine} eq 'Diesel' or $cfg{machine} eq 'Otto') {
                $error = "Machine Diese||Otto";
                return;
        }
        
        return bless {
                        machine => $cfg{machine},
                }, $class;
}