docs: private Variant loadVariantWhenAuthorized(final HttpServletRequest request) {
          // extract the pushApplicationID and its secret from the HTTP Basic
          // header:
          final String[] credentials = HttpBasicHelper.extractUsernameAndPasswordFromBasicHeader(request);
          final String variantID = credentials[0];
          final String secret = credentials[1];
  
          final Variant variant = genericVariantService.findByVariantID(variantID);
          if (variant != null && variant.getSecret().equals(secret)) {
              return variant;
          }
  
          // unauthorized...
          return null;
      }