Laravel - 使用查询功能会出错

I'm trying to take $max results. But sometimes the $max is NULL, so the query must returns all results.

I use this code:

$results = MyModel::whereIn('player', $players)->take(function($query) use ($max) {
    if (isset($max)) {
        $query->take($max);
    }
})->get();

But i get this error:

[ErrorException]                                       
  Object of class Closure could not be converted to int 

You may try this:

$query = MyModel::whereIn('player', $players);
if (!empty($max)) {
    $query->take($max);
}

$result = $query->get();