/**
* @param null|string $sibling
*
* @return Element|Tag|Field
*/
public function before($sibling = null)
{
$prev = $this->previousSibling;
if (is_null($sibling)) {
if ($prev) {
return $prev;
}
return $this;
}
return $this->parent()->insertBefore($this->ownerDocument->importNode($this->ownerDocument->check($sibling)), $this);
}
/**
* @param $element
*
* @return Element|Field|Tag
*/
public function before($element)
{
return $this->parent()->insertBefore($this->ownerDocument->importNode($this->ownerDocument->check($element)), $this);
}