public function testImageAttributes()
{
$s = new Svg('graph.svg', '640px', '480px', new Rgb(255, 0, 0));
$s->setFillColor(new Rgb(255, 0, 0));
$s->setBackgroundColor(new Rgb(0, 0, 255));
$s->setStrokeColor(new Rgb(0, 0, 0));
$s->setStrokeWidth();
$s->setStrokeWidth(5, 6, 4);
$s->setOpacity(50);
$this->assertEquals(640, $s->getWidth());
$this->assertEquals(480, $s->getHeight());
$this->assertEquals('px', $s->getUnits());
}