protected function buildChoiceLookupList($choices)
    {
        $array = array();

        foreach ($choices as $range => $choice) {
            $range = explode(':', $range);

            if (count($range) < 2) {
                $range[] = '';
            }

            $array[] = (object) array(
                'range' => (object) array(
                    'from' => $range[0],
                    'to' => $range[1],
                ),
                'string' => $choice
            );
        }

        return $array;
    }