code: function terminator(callback)
  {
    if (!Object.keys(this.jobs).length)
    {
      return;
    }
  
    // fast forward iteration index
    this.index = this.size;
  
    // abort jobs
    abort(this);
  
    // send back results we have so far
    async(callback)(null, this.results);
  }
docs: Terminates jobs in the attached state context
  
  @this  AsyncKitState#
  @param {function} callback - final callback to invoke after termination