public function testGetUpdated()
{
$xml = file_get_contents(__DIR__ . '/xml/worksheet.xml');
$worksheet = new Worksheet(new SimpleXMLElement($xml));
$this->assertTrue($worksheet->getUpdated() instanceof DateTime);
$this->assertEquals('2013-02-10 21:12:33', $worksheet->getUpdated()->format('Y-m-d H:i:s'));
}