#!/usr/bin/perl

package Caller;
sub new  { bless {}, 'Caller' }
sub call {      
    my( $self, $one ) = @_;
    $one->output;
}
sub output { "I am the Caller\n" }
1;

package Called;
use PadWalker 'peek_my';
sub new    {  bless {}, 'Called' }
sub output {
    my $caller = peek_my( 1 )->{ '$self' }; #$h->{ '$self' };
    print STDOUT $$caller->output();
}
1;
                                                                
                                                                
package main;

my $one = new Caller;
my $two = new Called;

$one->call( $two );
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Perfect, so long as it is indeed called $self.. :)

Makeshifts last the longest.

Hehe. Fair 'enough. But that can be ascertained without even looking at the original code, so I don't worry about it. ;) You're right, though, in that it can't be 100% generalized. I'd say this is still a Right Way To Do It.
--
Love justice; desire mercy.