docs: private InputStream getResourceAsStream(String resource) {
      InputStream is = getClass().getResourceAsStream(resource);
      // switch needed for testability
      if (is == null) {
        try {
          is = new FileInputStream(new File(resource));
        } catch (FileNotFoundException e) {
          // do nothing
        }
      }
      if (is == null) {
        throw new SelendroidException("The resource '" + resource + "' was not found.");
      }
      return is;
    }