public function writeLeaf(Leaf $leaf, $level = null)
{
$newLine = $this->isPretty() ? $this->getNewLine() : '';
$str = '';
if ($leaf instanceof Document) {
$str .= "<!DOCTYPE " . $leaf->getDocumentType() . ">" . $newLine;
}
return $str . parent::writeLeaf($leaf);
}
public function __clone()
{
parent::__clone();
foreach ($this->_children as $i => $child) {
$this->appendChild(clone $child);
}
}