If you have inheritance (e.g. ``User extends BaseUser``) and you validate

with the class name of the subclass (i.e. ``User``), then all constraints

in the ``User`` and ``BaseUser`` will be validated. However, if you validate

using the base class (i.e. ``BaseUser``), then only the constraints in

the ``BaseUser``group will be validated.

using the base class (i.e. ``BaseUser``), then only thedefaultconstraints in

the ``BaseUser``class will be validated.

To tell the validator to use a specific group, pass one or more group names

as the second argument to the ``validate()`` method::