muzich/vendor/friendsofsymfony/user-bundle/FOS/UserBundle/Resources/config/registration.xml

<?xml version="1.0" encoding="UTF-8" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>

        <service id="fos_user.registration.form" factory-method="createNamed" factory-service="form.factory" class="Symfony\Component\Form\Form">
            <argument>%fos_user.registration.form.name%</argument>
            <argument>%fos_user.registration.form.type%</argument>
            <argument>null</argument>
            <argument type="collection">
                <argument key="validation_groups">%fos_user.registration.form.validation_groups%</argument>
            </argument>
        </service>

        <service id="fos_user.registration.form.type" class="FOS\UserBundle\Form\Type\RegistrationFormType">
            <tag name="form.type" alias="fos_user_registration" />
            <argument>%fos_user.model.user.class%</argument>
        </service>

        <service id="fos_user.registration.form.handler.default" class="FOS\UserBundle\Form\Handler\RegistrationFormHandler" scope="request" public="false">
            <argument type="service" id="fos_user.registration.form" />
            <argument type="service" id="request" />
            <argument type="service" id="fos_user.user_manager" />
            <argument type="service" id="fos_user.mailer" />
            <argument type="service" id="fos_user.util.token_generator" />
        </service>

    </services>

</container>