docs: public Enumeration getInitParameterNames(int pScope) {
          switch (pScope) {
              case PageContext.PAGE_SCOPE:
                  return getServletConfig().getInitParameterNames();
              case PageContext.APPLICATION_SCOPE:
                  return getServletContext().getInitParameterNames();
              default:
                  throw new IllegalArgumentException("Illegal scope");
          }
      }