Symfony Dom Crawler Array Push Each

I am stumped by this one. I'm using Symfony's Dom crawler to filter some elements before extracting node data to push into array that can be converted to json. Yet the code below throws up a "Uncaught TypeError: array_push(): Argument #1 ($array) must be of type array" error.

    if($query == 'begin') {
      $persons = $crawler->filter('#content > table > tr > td > a');
        $trial = [];
            $persons->each(function (Crawler $node) {

                $holder['name'] = $node->text();
                $holder['url'] = $node->attr('href');
                print_r($holder['name']);
                // Correct value printed
                print_r($holder['url']);
                // Correct value printed
;               array_push($trial, $holder);

    });    
    var_dump($trial);

print_r shows the expected key-value yet the $trail array is null.

Yet the correct values are given when I try:

$persons->each(function (Crawler $node) {
                    echo "<div class='col col-lg-3'>
                            <a href='{$node->attr('href')}'>{$node->text()}</a>   
                          </div>";
                }); 

Seems the issue was with returning the values on the foreach loop. Managed to solve it with the code below:

if($query == 'begin') {
    
  $trial = [];

  $persons = $crawler->filter('#content > table > tr > td > a');

  $trial = $persons->each(function (Crawler $node)  {

    $holder['name'] = $node->text();
    $holder['url'] = $node->attr('href');

    return $holder;

}); 

Hat-tip to this thread - https://github.com/FriendsOfPHP/Goutte/issues/266