public function testNormalVisibilityShouldHaveNoExtensionElements()
 {
     $this->visibility->value = "http://schemas.google.com/g/2005#event.private";
     $this->assertEquals("http://schemas.google.com/g/2005#event.private", $this->visibility->value);
     $this->assertEquals(0, count($this->visibility->extensionElements));
     $newVisibility = new Zend_Gdata_Extension_Visibility();
     $newVisibility->transferFromXML($this->visibility->saveXML());
     $this->assertEquals(0, count($newVisibility->extensionElements));
     $newVisibility->extensionElements = array(new Zend_Gdata_App_Extension_Element('foo', 'atom', null, 'bar'));
     $this->assertEquals(1, count($newVisibility->extensionElements));
     $this->assertEquals("http://schemas.google.com/g/2005#event.private", $newVisibility->value);
     /* try constructing using magic factory */
     $gdata = new Zend_Gdata();
     $newVisibility2 = $gdata->newVisibility();
     $newVisibility2->transferFromXML($newVisibility->saveXML());
     $this->assertEquals(1, count($newVisibility2->extensionElements));
     $this->assertEquals("http://schemas.google.com/g/2005#event.private", $newVisibility2->value);
 }