code: @Override
      public Enumeration<String> getHeaderNames() {
          List<String> names = this.request.getHeaderNames();
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "getHeaderNames: " + names.size());
          }
          return Collections.enumeration(names);
      }
docs: /*
  @see javax.sHttpServletRequest#getHeaderNames()