public function isUnique()
    {
        $unique = false;

        //Get the unique states
        $states = $this->getData(true);

        if (!empty($states)) {
            $unique = true;

            //If a state contains multiple values the state is not unique
            foreach ($states as $state) {
                if (is_array($state) && count($state) > 1) {
                    $unique = false;
                    break;
                }
            }
        }

        return $unique;
    }