sub get_members {
   my $self     = shift;
   my $class    = ref $self;
   my $group_id = $self->id;

   my $quoted_group_id = $dbh->quote($group_id);

   my $members = $dbh->selectcol_arrayref(<<"  END_SQL");
     SELECT person_id 
     FROM   group_member 
     WHERE group_id = $quoted_group_id
   END_SQL

   foreach my $person_id ( @{$members} ) {
       my $person = bless {
           group_id  => $group_id,
           person_id => $person_id,
           name      => '',
           _members  => [],
       }, $class;
       push @members => $person;
   }
   return \@members;
}