*
* @since 1.21
*
- * @param string $languageCode
+ * @param string|null $languageCode
*/
public function setLanguageCode( $languageCode ) {
- if ( !Language::isValidCode( $languageCode ) ) {
+ if ( $languageCode !== null && !Language::isValidCode( $languageCode ) ) {
throw new InvalidArgumentException( "$languageCode is not a valid language code." );
}
$this->languageCode = $languageCode;