public function testPersistentFreezePropagates()
 {
     $cPers = new HTML_QuickForm2_ContainerImpl('cPersistent');
     $elPers = $cPers->appendChild(new HTML_QuickForm2_ElementImpl2('elPersistent'));
     $cPers->persistentFreeze(true);
     $this->assertTrue($cPers->persistentFreeze(), 'Container should have persistent freeze behaviour');
     $this->assertTrue($elPers->persistentFreeze(), 'Contained element should have persistent freeze behaviour');
     $cPers->persistentFreeze(false);
     $this->assertFalse($cPers->persistentFreeze(), 'Container should not have persistent freeze behaviour');
     $this->assertFalse($elPers->persistentFreeze(), 'Contained element should not have persistent freeze behaviour');
 }