public function testVisibilityWithValueToAndFromStringShouldMatch()
 {
     $this->visibility->value = "http://schemas.google.com/g/2005#event.private";
     $visibilityXml = $this->visibility->saveXML();
     $newVisibility = new Zend_Gdata_Extension_Visibility();
     $newVisibility->transferFromXML($visibilityXml);
     $newVisibilityXml = $newVisibility->saveXML();
     $this->assertTrue($visibilityXml == $newVisibilityXml);
     $this->assertEquals("http://schemas.google.com/g/2005#event.private", $this->visibility->value);
 }