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    sub transpose {
        my $rows     = shift;
        my $max_col  = @{ $rows->[0] } - 1;
        [ map { my $c=$_; [ map {($_->[$c])} @$rows ] } 0..$max_col ]
    }

    #    [ [ 0, 1 ]     <== transpose ==>   [ [ 0, 2 ]
    #    , [ 2, 3 ] ]                       , [ 1, 3 ] ]

    my $data_by_rows = transpose(
        [ \@ns_list, \@addr_list, \@ptr_list, \@uptime_list ]
    ) ;

    $data_by_rows = [
      [
...
        '366 days'
      ]
    ];

    my %ns_records =
        map {( shift @$_, [ @$_ ] )} @$data_by_rows;