public function testAddClippingPolygon()
{
$points = array(array('x' => 320, 'y' => 50), array('x' => 400, 'y' => 100), array('x' => 420, 'y' => 200), array('x' => 280, 'y' => 320), array('x' => 200, 'y' => 180));
$s = new Svg('graph.svg', '640px', '480px');
$s->drawClippingPolygon($points)->setClippingPath(0);
$this->assertEquals(640, $s->getWidth());
}