public function setMappingIndicator($mappingIndicator)
    {
        if (empty($mappingIndicator) === false && Format::isString256($mappingIndicator) === true) {
            $this->mappingIndicator = $mappingIndicator;
        } else {
            $msg = "The 'mappingIndicator' argument must be a non-empty string with at most 256 characters, '" . gettype($mappingIndicator) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }