public function testDuplicateIdHandling()
 {
     $e1 = new HTML_QuickForm2_ElementImpl2('dup1', array('id' => 'dup'));
     $e2 = new HTML_QuickForm2_ElementImpl2('dup2', array('id' => 'dup'));
     $c1 = new HTML_QuickForm2_ContainerImpl('dupContainer1');
     $c2 = new HTML_QuickForm2_ContainerImpl('dupContainer2');
     $c1->appendChild($e1);
     $c1->appendChild($e2);
     $this->assertEquals(2, count($c1), 'Element count is incorrect');
     $c1->removeChild($e1);
     $this->assertEquals(1, count($c1), 'Element count is incorrect');
     $this->assertSame($e2, $c1->getElementById('dup'));
     $c2->appendChild($e1);
     $c2->appendChild($e2);
     $c2->removeChild($e2);
     $this->assertEquals(1, count($c2), 'Element count is incorrect');
     $this->assertSame($e1, $c2->getElementById('dup'));
 }