@Override
        public boolean isValid(String ownerEmail, ConstraintValidatorContext context) {
            return !ownerEmailMandatory || !StringUtils.isEmpty(ownerEmail);
        }
This constraint class validates that owner email is non-empty, but only if configuration says
owner email is mandatory.
common/src/main/java/com/netflix/conductor/common/constraints/OwnerEmailMandatoryConstraint.java