ezcDocumentPdf documentation

I have followed the very simple example in the documentation:
$pdf = new ezcDocumentPdf();
$pdf->options->driver = new ezcDocumentPdfTcpdfDriver();

this throws an error, because ezcDocumentPdf generates ezcDocumentPdfHaruDriver already in the construct method.
So the right example would be:
$pdf = new ezcDocumentPdf(
new ezcDocumentPdfOptions(
array( 'driver' => new ezcDocumentPdfTcpdfDriver() )
)
);

I think this is an esier change, than move the default behavier to another place.