public function run()
{
$pt = new Point(0, 0);
$rect = new Rectangle(20, 10, 50, -20);
$tri = new Triangle(50, -20, 70, 0, 40, 30);
$circ = new Circle(80, 20, 50);
$shapes = array($pt, $rect, $tri, $circ);
$bbox = Shape::computeBoundingBox($shapes);
$this->check($bbox, array(0, 70, 130, -30));
$shapes = array();
$bbox = Shape::computeBoundingBox($shapes);
$this->check($bbox, array());
$shapes = array($pt);
$bbox = Shape::computeBoundingBox($shapes);
$this->check($bbox, array(0, 0, 0, 0));
$shapes = array($rect, $rect, $rect, $rect);
$bbox = Shape::computeBoundingBox($shapes);
$this->check($bbox, $rect->getCoords());
$shapes = array($tri);
$bbox = Shape::computeBoundingBox($shapes);
$this->check($bbox, array(40, 30, 70, -20));
}