public function testJson()
{
$expected = '{"type":"Polygon","coordinates":[[[0,0],[10,0],[10,10],[0,10],[0,0]],[[0,0],[10,0],[10,10],[0,10],[0,0]]]}';
$rings = array(array(array(0, 0), array(10, 0), array(10, 10), array(0, 10), array(0, 0)), array(array(0, 0), array(10, 0), array(10, 10), array(0, 10), array(0, 0)));
$polygon = new Polygon($rings);
$this->assertEquals($expected, $polygon->toJson());
}