code>ConstraintViolation</code> is returned
     after calling <a href="Validator.html#validateValue(java.lang.Class,java.lang.String,java.lang.Object,java.lang.Class...)"><code>Validator.validateValue(Class, String, Object, Class[])</code></a>
     </li>
     <li>the object the method is executed on if it is
     a method parameter, cross-parameter or return value constraint or a
     container element constraint hosted on a method parameter or return value</li>
     <li><code>null</code> if it is a constr