Select Code to Download

sub list {
    my $self = shift @_;
...

    return wantarray ? @$aref : $aref;
}

    my @population = $self->list("_population");

sub remove {
    my $self   = shift;
...
    $self->{$type} = [ grep { $target ne $_ } @{$self->{$type}} ];
    return;
}