Delete data in MongoDB

Code
<?php

$m 
= new MongoClient();

$test $m->selectDb('test');

$coll $test->selectCollection('my_table');

$success $coll->remove(array(
    
'_id' => new MongoId("54204806895f69383a8b4567")
));

var_dump($success);
Result
array(4) {
["n"]=>
int(1)
["connectionId"]=>
int(11)
["err"]=>
NULL
["ok"]=>
float(1)
}
Used Versions
PHP 7.1, Zend 3.0, Symfony 3.2, Laravel 5.2, PHPUnit 5.6, Doctrine 2.6