my $sort_by_str = $sort_spec->{columns}->{$sort_by};
$sort_by_str = [ $sort_by_str ] unless ref($sort_by_str) eq 'ARRAY';
- # generaate tiebreaker
+ # generate tiebreaker
push @$sort_by_str, @{ $sort_spec->{tiebreaker} };
$sort_by_str = join(', ', map { "${_} ${sort_dir_str}${nulls_str}" } @{ $sort_by_str });