def download(label_id)
      download_url = File.join(LABEL_URL, "#{label_id}.pdf")
      response = connection.get download_url
      StringIO.new(response.body)
    end
def download(label_id)
      download_url = File.join(LABEL_URL, "#{label_id}.pdf")
      response = connection.get download_url
      StringIO.new(response.body)
    end
Download label
 @param label_id [String]
 @return Object of label