title: Apache POI. Copying sheets
body: <p>I'm using apache poi to create an excel document. To create new sheet in workbook I write next code:</p>
  
  <pre><code>Workbook wb = new HSSFWorkbook(); 
  Sheet sh = wb.createSheet();
  </code></pre>
  
  <p>this code create and add sheet to workbook. But I want to create sheet formerly and then add it to workbook. Smth like this: </p>
  
  <pre><code>Sheet sh = new HSSFSheet();
  wb.addSheet(sh);
  </code></pre>
  
  <p>I need such thing, because I want to copy data from one sheet of one workbook to another sheet of another workbook(Workbook interface has method <code>Sheet cloneSheet(int)</code>). But Workbook interface doesn't have method like addSheet(Sheet sh). 
  Also HSSFWorkbook is final class so I can't extend it to implement add method
  How can I do this?</p>