private function appendItem($url, $lastMod, $priority, $changeFreq):void
    {
        $this->create('append', $url, $lastMod, $priority, $changeFreq);
    }
private function appendItem($url, $lastMod, $priority, $changeFreq):void
    {
        $this->create('append', $url, $lastMod, $priority, $changeFreq);
    }
private function appendItem ( $ url , $ lastMod , $ priority , $ changeFreq ) : void { $ this -> create ( 'append' , $ url , $ lastMod , $ priority , $ changeFreq ) ; }
Append item to sitemap.

@param (string) $url        Valid url.
@param (string) $lastMod    Last modify.
@param (float)  $priority   Priority.
@param (string) $changeFreq changeFreq.

@since 3.0.0

@return void
Append item to sitemap .