code: @OverrideOnDemand
    protected void logInvalidRequestSetup (@Nonnull final String sMsg, @Nonnull final HttpServletRequest aHttpRequest)
    {
      log (sMsg + ":\n" + RequestLogger.getRequestDebugString (aHttpRequest).toString ());
    }
docs: This method logs errors, in case a HttpServletRequest object is missing basic
  information or uses unsupported values for e.g. HTTP version and HTTP method.
  
  @param sMsg
  The concrete message to emit. May not be <code>null</code>.
  @param aHttpRequest
  The current HTTP request. May not be <code>null</code>.