package Foo;

my $_private = sub { ... };
my _private = sub { ... };

sub foo {
    my $self = shift;
    
    # we can specify the full package name
    $self->Foo::_private();
    
    # we can call as a subroutine
    _private($self);
    
    # we can use lexically scoped subs
    $self->$_private();
};

##</code><code>##

package Foo;

sub Foo::private::method { ... };

sub foo {
    my $self = shift;
    $self->Foo::private::method { ... };
};

##</code><code>##

sub Foo::MY::method { ... };

sub foo {
    my $self = shift;
    $self->MY::method();
};

##</code><code>##

package MY;

sub AUTOLOAD {
    my $self = shift;
    our $AUTOLOAD;
    my $method = caller() . "::$AUTOLOAD";
    $self->$method(@_);
};

##</code><code>##

sub MY::method { ... };

##</code><code>##

sub MyLongPackageName::MY::method { ... };

##</code><code>##

package MY;
use strict;
use warnings;

my $Imported_from;
sub import { $Imported_from = caller };

use Filter::Simple;
FILTER_ONLY code => sub { s/(\w+::)*MY::/${Imported_from}::MY::/gs };

1;

##</code><code>##

package Foo;
use MY;

sub new { bless {}, shift };

sub hello {
    my $self = shift;
    $self->MY::greet_world("hi");
};

sub MY::greet_world {
    my ($self, $greeting) = @_;
    print "$greeting world\n";
};


package Bar;
use base qw(Foo);
use MY;

sub new {
    my $class = shift;
    $class->MY::greet_world();
    return $class->SUPER::new(@_);
};

sub MY::greet_world {
    print "A new Bar has entered the world\n";
};