<?PHP declare(strict_types = 1); /** * Exception thrown in case a library of congress link refers to the subject * headings (subject headings are a dedicated, full vocabulary according to * md's definition). */ final class MDInvalidNodaLinkLocIdIsSh extends MDInvalidNodaLinkException { /** * Error message. * * @return string */ public function errorMessage() { //error message return 'Inputs are not valid.'; } }