title: How at a time one row can expand in <p:dataTable>?
body: <p>In my application I have a <code>&lt;p:datatable&gt;</code> with <code>rowExpansion</code> column. I have a requirement to open a single row at a time. If anyone tries to expand second row, remaining first row expanded then one message will be generated saying <code>First close the expanded row and then open another row</code>.</p>
  
  <p>How this can be implemented ? Any pointer will be very helpful to me. Thanks </p>