Google\Spreadsheet\Worksheet::getUpdated PHP Method

    public function getUpdated()
    {
        return new DateTime($this->xml->updated->__toString());
    }

 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'));
 }