use strict;
use warnings;

package Bar;
use Devel::Peek 'Dump';

sub new { bless [], shift }

sub bar { print "Hi, I'm a bar instance\n\n" }

sub dump 
{
    print "This is my ID card:\n";
    Dump( shift )
}

package Foo;

sub new 
{
    my $bar = Bar->new();

    bless { bar => $bar }, shift;
}

sub DESTROY 
{
    my $self = shift;
    $self->{ bar }->bar();
    $self->{ bar }->dump();
}

package main;

my $f = Foo->new();