code: public static Action resourceContent(String resourcePath, String charset) {
          URL resource = Action.class.getClassLoader().getResource(resourcePath);
          if (resource == null) {
              throw new IllegalArgumentException(String.format("Resource %s not found.", resourcePath));
          }
          Action charsetAction = charset == null ? noop() : charset(Charset.forName(charset));
          return composite(resourceContent(resource), charsetAction);
      }
docs: Combines {@link #resourceContent(String)} and {@link #charset(String)}