code: @Override
    public long getSize() throws ResourceNotAvailableException {
  
      try {
        // return getUrl().openConnection().getContentLengthLong();
        return getUrl().openConnection().getContentLength();
      } catch (IOException e) {
        throw new ResourceNotAvailableException(e, getPath());
      }
    }
docs: {@inheritDoc}
  
  This is a default implementation. Override if there is a more performing way to implement this.