object that's actually the one being validated.

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

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

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

validate using the base class(i.e. ``BaseUser``), then only the default

constraints in the ``BaseUser`` class will be validated.

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

in the ``User`` will be validated.To validate the parent constraints as

  well you need to provide multiple groups(i.e ``User`` and ``BaseUser``) or

   ``Default``.

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

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