public function testSource($fileName)
{
$content = $this->getContent($fileName);
$item = $this->getItem($content);
$expected = $this->getFistAttributeFromXpath($content, "*/ns:link[@rel='" . AtomParser::SOURCE_LINK_ATTR . "']", 'href');
$this->assertEquals($expected, $item->getSource(), 'Fail asserting that first element of ' . $fileName . ' has source "' . $expected . '"');
}