public function guessMinLengthForConstraint(Constraint $constraint)
    {
        switch (get_class($constraint)) {
            case 'Symfony\Component\Validator\Constraints\Length':
                if (is_numeric($constraint->min)) {
                    return new ValueGuess($constraint->min, Guess::HIGH_CONFIDENCE);
                }
                break;
            case 'Symfony\Component\Validator\Constraints\Type':
                if (in_array($constraint->type, array('double', 'float', 'numeric', 'real'))) {
                    return new ValueGuess(null, Guess::MEDIUM_CONFIDENCE);
                }
                break;
            case 'Symfony\Component\Validator\Constraints\Range':
                if (is_numeric($constraint->min)) {
                    return new ValueGuess(strlen((string) $constraint->min), Guess::LOW_CONFIDENCE);
                }
                break;
        }
    }