title: PHPOffice\Excel Styling Worksheet without a Spreadsheet Object
body: <p>I'm having trouble styling cells in a worksheet object that doesn't yet belong to a spreadsheet object. Is this possible? It doesn't appear to be possible using the getStyle() method since this method calls functions in the parent spreadsheet. Maybe there is another method?</p>
  
  <p>Worksheet class:</p>
  
  <pre><code>    class MyWorksheet extends \PHPOffice\PHPSpreadsheet\Worksheet\Worksheet {
  
          public function something() {
              $this-&gt;setCellValue('A1', 'Something');
              $this-&gt;getStyle('A1')-&gt;ApplyFromArray([
                  'font' =&gt; ['bold' =&gt; true]
              ]);
           } 
      }
  </code></pre>
  
  <p>When something() is executed it results in a setActiveSheetIndex() on null exception.</p>