protected function normalizeCastString($cast)
    {
        switch ($cast) {

            case 'bool':
            case 'boolean':
                $cast = AttributeCast::BOOLEAN;
                break;

            case 'decimal':
            case 'double':
            case 'float':
            case 'real':
                $cast = AttributeCast::FLOAT;
                break;

            case 'int':
            case 'integer':
                $cast = AttributeCast::INTEGER;
                break;

            case 'date':
            case 'datetime':
                $cast = AttributeCast::DATE;
                break;
        }

        return $cast;
    }