public function getSessionId() : string
    {
        //if its empty get it from the relationship, else get it from the property
        return empty($this->session_id) ? $this->getSession(['order' => 'time desc'])->session_id : $this->session_id;
    }
public function getSessionId() : string
    {
        //if its empty get it from the relationship, else get it from the property
        return empty($this->session_id) ? $this->getSession(['order' => 'time desc'])->session_id : $this->session_id;
    }
public function getSessionId ( ) : string { //if its empty get it from the relationship, else get it from the property return empty ( $ this -> session_id ) ? $ this -> getSession ( [ 'order' => 'time desc' ] ) -> session_id : $ this -> session_id ; }
get the user session id

@return string
get the user session id