public function addWithOption($key, $option, $value, $append = true)
    {
        if (!isset($this->container[$key])) {
            $this->container[$key] = array(
                $option => $value
            );

        } else {
            // Option already exists, so now depending on $append 
            if ($append === true) {
                $this->container[$key][$option] = $value;
            }
        }

        return $this;
    }