title: How to pass main report data source to subreport (JasperReports)?
body: <p>I'm using JasperReports and I fill the <code>JRDataSource</code> for ther report.
  Now, I want to pass the main <code>REPORT_DATA_SOURCE</code> to the subreport. How can I do this?</p>
  
  <p>As far as I know the <code>REPORT_DATA_SOURCE</code> is a consumable object, so it can only be used once, right?. Can I copy this data source and pass it?</p>
  
  <p>BTW: I use iReport for creating the layout.</p>