title: sheetjs xlsx, How to write merged cells?
body: <p>I need to create a xlsx with merged cells using sheetjs.</p>
  
  <p><strong>data</strong>:</p>
  
  <pre><code>[
    {
      "id": "nick",
      "items": [
        {
          "name": "ball"
        },
        {
          "name": "phone"
        }
      ]
    },
    {
      "id": "jack",
      "items": [
        {
          "name": "pen"
        },
        {
          "name": "doll"
        }
      ]
    }
  ]
  </code></pre>
  
  <p><strong>My code:</strong></p>
  
  <pre><code>var ws = XLSX.utils.json_to_sheet(data);
  var wb = XLSX.utils.book_new();
  XLSX.utils.book_append_sheet(wb, ws, "");
  var wbout = XLSX.write(wb, {bookType:'xlsx', type:'array'});
  saveAs(new Blob([wbout],{type:"application/octet-stream"}), filename + ".xlsx");
  </code></pre>
  
  <p><strong>The result I want to get:</strong></p>
  
  <p><a href="https://i.stack.imgur.com/Fme4z.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Fme4z.png" alt="result"></a></p>
  
  <p>How do I get this result?</p>
  
  <p>... Thank you</p>