sub sort_results {
  #========================================
  # Sort results in descending order       
  # by date and ascending by document name
  # within a date.
  #========================================
  my $self = shift; 
  my $database = $self->{_database};

  my $sort_sub = sub {
    $database->[$b]->{numeric_date} <=> $database->[$a]->{numeric_date}
      or
    $database->[$a]->{document_name} cmp $database->[$b]->{document_name}
      or
    $a <=> $b;
  };

  @{$self->{_search_hits}} = sort $sort_sub @{$self->{_search_hits}};                    

}