public function testPointersToNodesAreNotLost()
{
$actual = array(new SimpleDOM('<child letter="c" />'), new SimpleDOM('<child letter="d" />'), new SimpleDOM('<child letter="e" />'), new SimpleDOM('<child letter="a" />'), new SimpleDOM('<child letter="b" />'));
$c = $actual[0];
$d = $actual[1];
$e = $actual[2];
$a = $actual[3];
$b = $actual[4];
SimpleDOM::sort($actual, '@letter');
$a['old_letter'] = 'a';
$b['old_letter'] = 'b';
$c['old_letter'] = 'c';
$d['old_letter'] = 'd';
$e['old_letter'] = 'e';
$expected = array(new SimpleDOM('<child letter="a" old_letter="a" />'), new SimpleDOM('<child letter="b" old_letter="b" />'), new SimpleDOM('<child letter="c" old_letter="c" />'), new SimpleDOM('<child letter="d" old_letter="d" />'), new SimpleDOM('<child letter="e" old_letter="e" />'));
$this->assertEquals($expected, $actual);
}