public function listStatus()
    {
        $data = [];

        // create a reflection class to get constants
        $refl = new ReflectionClass(get_called_class());
        $constants = $refl->getConstants();

        // check for status constants (e.g., STATUS_ACTIVE)
        foreach ($constants as $constantName => $constantValue) {

            // add prettified name to dropdown
            if (strpos($constantName, "STATUS_") === 0) {
                $prettyName = str_replace("STATUS_", "", $constantName);
                $prettyName = Inflector::humanize(strtolower($prettyName));
                $data[$constantValue] = $prettyName;
            }
        }

        return $data;
    }