Adds a constraint to this element.
Constraint $constraint:
Overrides ElementMetadata::addConstraint
public function addConstraint(Constraint $constraint) {
if (!in_array(Constraint::CLASS_CONSTRAINT, (array) $constraint
->getTargets())) {
throw new ConstraintDefinitionException(sprintf('The constraint %s cannot be put on classes', get_class($constraint)));
}
$constraint
->addImplicitGroupName($this
->getDefaultGroup());
parent::addConstraint($constraint);
}