public function saveAsFunctionality($project_id)
 {
     $functionality = new Functionality();
     $functionality->project_id = $project_id;
     $functionality->name = $this->name;
     $functionality->price = round($this->price, 2);
     $functionality->amount = 1;
     $functionality->description = $this->description;
     $functionality->deleted = false;
     if (!$functionality->validate()) {
         return false;
     } else {
         return $functionality->save();
     }
 }