gistfile1.php

<?php

/**
 * @ORM/Entity
 */
class Product
{
    /**
     * @OneToMany(targetEntity="Price", mappedBy="product", cascade={"refresh"})
     */
    public $prices;
    
    /**
     * @OneToMany(targetEntity="Color", mappedBy="product", cascade={"refresh"}, fetch="EAGER")
     */
    public $colors;
}

$product = //fetch a product from db through doctrine and hydrate it
$em->refresh($product); // $product->prices is empty
                        // because the BasicEmptyPersister unwrap the PersistentCollection (thus not initialize it)
                        // and refresh each elements (which it doesn't have, because it was not initialized)
                        // $product->colors is correctly refreshed and contains same colors than in DB