Filtering a PersistentCollection and then persist the changes.

test.php

<?php
// ----------- This is a method part of the Order entity, located in Order.php ---------------
    /**
     * Rejects all attributes with the provided code from the order.
     *
     * @param string $code
     */
    public function rejectAttribute($code)
    {
        $this->attributes = $this->attributes->filter(function ($attribute) use ($code) {
            return $attribute->getCode() !== $code;
        });
        
        // Dumping $this->attributes here show the expected result
    }

// ------------- Example usage ----------------- //
$order->rejectAttribute("shippingMethod");
$em->persist($order);
$em->flush();
  
// Refetching the order from the ORM and dumping the attributes shows nothing was persisted and the collection remain intact.