use warnings;
use strict;

package Obj;

use Exporter qw(import);
our @EXPORT_OK = qw(foo);

sub new {
    return bless {}, shift;
}
sub foo {
    my $self;
    if ($_[0] eq __PACKAGE__ || ref $_[0] eq __PACKAGE__){
        $self = shift;
    }
    my ($x, $y) = @_;
    return $x * $y;
}