code: public FormValidation doCheckNormalThreshold(@QueryParameter final String highThreshold, @QueryParameter final String normalThreshold) {
          return VALIDATION.validateNormal(highThreshold, normalThreshold);
      }
docs: Performs on-the-fly validation on threshold for normal warnings.
  
  @param highThreshold
  the threshold for high warnings
  @param normalThreshold
  the threshold for normal warnings
  @return the validation result