docs: private static Reader readerFromUrl(String resourceName) throws IOException {
      URL resourceUrl = TemplateVars.class.getResource(resourceName);
      InputStream in;
      try {
        if (resourceUrl.getProtocol().equalsIgnoreCase("file")) {
          in = inputStreamFromFile(resourceUrl);
        } else if (resourceUrl.getProtocol().equalsIgnoreCase("jar")) {
          in = inputStreamFromJar(resourceUrl);
        } else {
          throw new AssertionError("Template fallback logic fails for: " + resourceUrl);
        }
      } catch (URISyntaxException e) {
        throw new IOException(e);
      }
      return new InputStreamReader(in, StandardCharsets.UTF_8);
    }