iTop/lib/symfony/framework-bundle/Tests/Fixtures/Validation/Resources/person.xml

<?xml version="1.0" encoding="UTF-8" ?>
<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                    xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">

    <class name="Symfony\Bundle\FrameworkBundle\Tests\Fixtures\Validation\Person">
        <property name="eyeColor">
            <constraint name="Choice">
                <option name="choices">
                    <value>brown</value>
                    <value>green</value>
                    <value>blue</value>
                </option>
                <option name="message">Choose a valid eye color.</option>
            </constraint>
        </property>
    </class>

    <class name="Symfony\Bundle\FrameworkBundle\Tests\Fixtures\Validation\Article">
        <property name="category">
            <constraint name="Choice">
                <option name="choices">
                    <value>other</value>
                </option>
                <option name="message">This should be ignored.</option>
            </constraint>
        </property>
    </class>
</constraint-mapping>