my $docids = PublicInbox::Search::mset_to_artnums($self->{es}, $mset);
my $ibx_id = $self->{-ibx_id} //= _ibx_id($self);
my $qmarks = join(',', map { '?' } @$docids);
my $docids = PublicInbox::Search::mset_to_artnums($self->{es}, $mset);
my $ibx_id = $self->{-ibx_id} //= _ibx_id($self);
my $qmarks = join(',', map { '?' } @$docids);