use strict;
use warnings;

package Base;

sub new {
    my ($class, %args) = @_;
    
    return bless \%args, $class;
}


sub DoIt {
    my ($self) = @_;
    
    printf "In the base DoIt for an object of class %s\n", ref $self;
}


sub DoOther {
    my ($self) = @_;
    
    printf "In the base DoOther for an object of class %s\n", ref $self;
}


package Derived;

use parent 'Base';

sub new {
    my ($class, %args) = @_;
    
    return $class->SUPER::new (%args);
}


sub DoIt {
    my ($self) = @_;
    
    printf "In the derived DoIt for an object of class %s\n", ref $self;
    $self->SUPER::DoIt ();
}


sub DoExtra {
    my ($self) = @_;
    
    printf "In the derived DoExtra for an object of class %s\n", ref $self;
}


package main;

my $obj = Derived->new ();

$obj->DoIt ();
$obj->DoOther ();
$obj->DoExtra ();