public function set($variable, $value = null)
    {
        if (is_array($variable)) {
            $this->userData = array_merge($this->userData, $variable);
        } else if (is_object($variable)) {
            $this->userData = array_merge($this->userData, (array)$variable);
        } else {
            if ($value === null) {
                unset($this->userData[$variable]);
            } else {
                $this->userData[$variable] = $value;
            }
        }
    }