code: function isParent($tag, $recursive = false) {
  		return ($this->hasParent($tag, $recursive) === ($tag !== null));
  	}
docs: Find out if node is parent of a certain tag
  @param DomNode|string $tag Match against parent, string to match tag, object to fully match node
  @param bool $recursive
  @return bool
  @see hasParent()