docs: static void throwIfUnrecognizedParamName(Enumeration initParamNames) throws ServletException {
          final Set<String> recognizedParameterNames = new HashSet<String>();
          recognizedParameterNames.add(ALLOW_MULTI_VALUED_PARAMETERS);
          recognizedParameterNames.add(PARAMETERS_TO_CHECK);
          recognizedParameterNames.add(CHARACTERS_TO_FORBID);
  
          while (initParamNames.hasMoreElements()) {
              final String initParamName = (String) initParamNames.nextElement();
              if (!recognizedParameterNames.contains(initParamName)) {
                  throw new ServletException(
                          "Unrecognized init parameter ["
                                  + initParamName
                                  + "].  Failing safe.  Typo"
                                  + " in the web.xml configuration? "
                                  + " Misunderstanding about the configuration "
                                  + RequestParameterPolicyEnforcementFilter.class.getSimpleName()
                                  + " expects?");
              }
          }
      }