package My::LibXML::Document;

# all method calls in this class should be 
# delegated to the object in 'base'
use Class::Delegation send => -ALL, to => 'base';

sub new {
	my $class = shift;
	my $self = bless {
		base		=>	XML::LibXML::Document->new('1.0','UTF8'),
		listeners	=>	[1,2,3],	# or whatever
	}, $class;
	return($self);
};

sub listeners {
	my $listeners = shift->{listeners};
	return(@$listeners);
};


package main;

my $o = My::LibXML::Document->new;
print $o->encoding, "\n";   # same as doing $o->{base}->encoding;
print join(", ", $o->listeners), "\n";