final public function walk(Callable $callback, $userdata = null)
	{
		array_walk($this->{self::MAGIC_PROPERTY}, $callback);
		return $this;
	}
final public function walk(Callable $callback, $userdata = null)
	{
		array_walk($this->{self::MAGIC_PROPERTY}, $callback);
		return $this;
	}
final public function walk ( Callable $ callback , $ userdata = null ) { array_walk ( $ this -> { self :: MAGIC_PROPERTY } , $ callback ) ; return $ this ; }
Apply a user supplied function to every member of an array
@param  Callable $callback Typically, callback takes on two parameters. ($value, $index)
@param  mixed    $userdata Optional third paramater for third paramater of $callback
@return self
Apply a user supplied function to every member of an array