public function testWriter()
{
$writer = new Writer();
$writer->addService('http://www.myopenid.com/server', array('http://specs.openid.net/auth/2.0/signon'));
$writer->addService('http://www.myopenid.com/server', array('http://specs.openid.net/auth/2.0/signon'), 20);
$actual = $writer->toString();
$expected = <<<'XML'
<?xml version="1.0" encoding="UTF-8"?>
<xrds:XRDS xmlns="xri://$xrd*($v*2.0)" xmlns:xrds="xri://$xrds">
<XRD>
<Service>
<Type>http://specs.openid.net/auth/2.0/signon</Type>
<URI>http://www.myopenid.com/server</URI>
</Service>
<Service priority="20">
<Type>http://specs.openid.net/auth/2.0/signon</Type>
<URI>http://www.myopenid.com/server</URI>
</Service>
</XRD>
</xrds:XRDS>
XML;
$this->assertXmlStringEqualsXmlString($expected, $actual);
}