public function firstDN(): Name
    {
        $gn = $this->firstOf(GeneralName::TAG_DIRECTORY_NAME);
        if (!$gn instanceof DirectoryName) {
            throw new \RuntimeException(
                DirectoryName::class . " expected, got " . get_class($gn));
        }
        return $gn->dn();
    }
public function firstDN(): Name
    {
        $gn = $this->firstOf(GeneralName::TAG_DIRECTORY_NAME);
        if (!$gn instanceof DirectoryName) {
            throw new \RuntimeException(
                DirectoryName::class . " expected, got " . get_class($gn));
        }
        return $gn->dn();
    }
public function firstDN ( ) : Name { $ gn = $ this -> firstOf ( GeneralName :: TAG_DIRECTORY_NAME ) ; if ( ! $ gn instanceof DirectoryName ) { throw new \ RuntimeException ( DirectoryName :: class . " expected, got " . get_class ( $ gn ) ) ; } return $ gn -> dn ( ) ; }
Get value of the first 'directoryName' type.

@return Name
Get value of the first directoryName type .