<?php
  
  namespace Illuminate\Contracts\Queue;
  
  interface Monitor
  {
      /**
       * Register a callback to be executed on every iteration through the queue loop.
       *
       * @param  mixed  $callback
       * @return void
       */
      public function looping($callback);
  
      /**
       * Register a callback to be executed when a job fails after the maximum amount of retries.
       *
       * @param  mixed  $callback
       * @return void
       */
      public function failing($callback);
  
      /**
       * Register a callback to be executed when a daemon queue is stopping.
       *
       * @param  mixed  $callback
       * @return void
       */
      public function stopping($callback);
  }