public function goNext(){
    $currentOrder = $this->node_orders;
    $nextNodeOrder = $currentOrder + 1;

    $status = 'proceed';
    $maxOrder = $this->flow()->first()->nodes()->count();
    if($nextNodeOrder > $maxOrder){
      $status = 'completed';
      $nextNodeOrder = $maxOrder+1;
    }
    $this->node_orders = $nextNodeOrder;
    $this->status = $status;
    $this->save();
    Log::error($this->errors()->all());
  }