code: public void addWarningMsgs(final Set<String> msgs) {
      if (msgs != null) {
        this._warningMsgs.addAll(msgs);
        if (!msgs.isEmpty() && this._errorMsgs.isEmpty()) {
          this._status = ValidationStatus.WARN;
        }
      }
    }
docs: Add a message with status level being {@link ValidationStatus#WARN}