ModelBundle/Validator/Constraints/CheckPublishingDateValidator.php
public function validate($value, Constraint $constraint)
    {
        if ($value instanceof AutoPublishableInterface &&
            $value->getPublishDate() instanceof \DateTime &&
            $value->getUnpublishDate() instanceof \DateTime &&
            $value->getPublishDate()->getTimestamp() > $value->getUnpublishDate()->getTimestamp()
        ) {
            $this->context->buildViolation($constraint->message)
                ->atPath('unpublishDate')
                ->addViolation();
        }
    }
public function validate($value, Constraint $constraint)
    {
        if ($value instanceof AutoPublishableInterface &&
            $value->getPublishDate() instanceof \DateTime &&
            $value->getUnpublishDate() instanceof \DateTime &&
            $value->getPublishDate()->getTimestamp() > $value->getUnpublishDate()->getTimestamp()
        ) {
            $this->context->buildViolation($constraint->message)
                ->atPath('unpublishDate')
                ->addViolation();
        }
    }
Checks if the passed value is valid.

@param AutoPublishableInterface $value The value that should be validated
@param Constraint               $constraint The constraint for the validation