/**
  * Returns a new grid instance of the specified assets meters.
  *
  * @param int|string $id
  *
  * @return \Cartalyst\DataGrid\DataGrid
  */
 public function grid($id)
 {
     $columns = ['meters.id', 'meters.name', 'meters.user_id', 'meters.metric_id', 'meters.created_at'];
     $settings = ['sort' => 'created_at', 'direction' => 'desc', 'threshold' => 10, 'throttle' => 10];
     $transformer = function (Meter $meter) use($id) {
         return ['id' => $meter->id, 'name' => $meter->name, 'user' => $meter->user ? $meter->user->full_name : '<em>None</em>', 'metric' => $meter->metric ? $meter->metric->name : '<em>None</em>', 'reading' => $meter->getLastReadingWithMetricAttribute(), 'comment' => $meter->getLastCommentAttribute(), 'created_at' => $meter->created_at, 'view_url' => route('maintenance.assets.meters.show', [$id, $meter->id])];
     };
     return $this->asset->gridMeters($id, $columns, $settings, $transformer);
 }