public function title($title, $url = null)
    {
        $this->title = $title;
        $this->url = $url;

        return $this;
    }
public function title($title, $url = null)
    {
        $this->title = $title;
        $this->url = $url;

        return $this;
    }
public function title ( $ title , $ url = null ) { $ this -> title = $ title ; $ this -> url = $ url ; return $ this ; }
Set the title of the attachment.

@param  string  $title
@param  string|null  $url
@return $this
Set the title of the attachment .