my $collection = Collection->new({ 'sorter' => Sort::mysorter });

sub new
{
  my ($self, $options) = @_;
  .  .  .
  $self->{sorter} = \&$options->{sorter};
}


##</code><code>##

my $collection = Collection->new({ 'sorter' => \&Sort::mysorter });

sub new
{
  my ($self, $options) = @_;
  .  .  .
  $self->{sorter} = $options->{sorter};
}


##</code><code>##

$self->sorter($stuffToSort);