package Facade::Base;

sub new {
    my $class = shift;
    my ($main) = @_;

    return bless \$main, $class;
}

package Facade::One;
use base 'Facade::Base';

sub example {
    my $self = shift;

    # foo() is a method on the object I expect to facade over
    $$self->foo( @args );
}

package main;

my $datastructure = Main::Class->new( %params );

my $facade1 = Facade::One->new( $datastructure );

# Now, I can call Facade::One's methods on $facade1.
# I can also change the facade by doing something like:
my $facade2 = Facade::Two->new( $$facade1 );