my @tocheck = grep { ref eq 'ARRAY' } values %{$self};
my %count;
for (@tocheck) {
    my %uniq;
    @uniq{@$_} = ();
    for (keys %uniq) {
        $count{$_}++;
    }
}
my @in_all = grep { $count{$_} == @tocheck } keys %count;