%% my $default = { color => '#000000', size => 14 };
%% format(basic => $default.merge({bold => true(),align => 'left'}));

{
   "selection"  : 0,
   "worksheets" : [
      {
         "column_widths" : [ 14.6, 18.5, 15.8, 12.2 ],
         "name"          : "Merge Report 1",
         "selection"     : [ 1, 9 ],
         "row_heights"   : [ 25, 18, 18, 18 ],
         "cells"         : [
            %% for $headers -> $header {
            [
               [% c($header.value1, "basic") %],
               [% c($header.value2, "basic") %],
               [% c($header.value3, "basic") %],
               [% c($header.value4, "basic") %]
            ],
            %% }
            %% for $rows -> $row {
            [
               [% c($row.value1, "basic", "number") %],
               [% c($row.value2, "basic", "number") %],
               [% c($row.value3, "basic", "number") %],
               [% c($row.value4, "basic", "number") %]
            ],
            %% }
            [
                [% c(0, "basic", "number" ) %]
            ]
         ],
         "merge" : [
            [% merge('Merged Header', 'basic', 'string','A1:D1') %],
            [% merge($rows.map(-> $a {$a.value1}).reduce(-> $a,$b {$a + $b}), 'basic', 
                 'number', 
                 'A4:D4', formula => 'SUM(A2:A3)') %]
         ] 
      }
   ]
}