#!/usr/bin/perl

use strict;
use warnings;

use User;

my $test = User->new(name => "user1", team=> "teamalpha");
my $test2 = User->new(name => "user2", team=> "teambeta");

$test->test();
$test2->test();




package User;

use strict;
use warnings;

my $references;

sub new {

    my ($class, %arg) = @_;
    my $objref = {
        _name                   => $arg{name}               || "unknown"
        _team                   => $arg{team}               || "unknown"

    };
    bless $objref, $class;

    $references->{$objref} = "value";

    return $objref;
}

sub test {
    my $self = shift @_;
    foreach my $object (keys %$ds) {
        if($self->{_team} ne $object->{_team}) {
             #find opposing team
             #do something to $object
        }
    }
}