package Foo;
use Mixin qw(frobnicate);

sub new {
  bless {}, shift;
}

package main;

my $foo = Foo->new();
$foo->frobnicate();

##</code><code>##

package Mixin;
use base 'Exporter';
our @EXPORT_OK = qw(frobnicate);

sub frobnicate { print "frobnicating!\n"; }

##</code><code>##

package Mixin;
use base 'Exporter';
our @EXPORT_OK = qw(frobnicate);

sub frobnicate { 
    my($self) = @_;

    $self->frobnerize(); 
}

sub frobnerize {
    my($self) = @_;
    print "frobnerizing!\n";
}

1;

##</code><code>##

use Mixin qw(frobnicate frobnerize);