code: def attach_binary(self, content, filename):
          
          content_type = guess_content_type(filename)
          payload = {"Name": filename, "Content": b64encode(content).decode("utf-8"), "ContentType": content_type}
          self.attach(payload)
docs: Attaches given binary data.
  
          :param bytes content: Binary data to be attached.
          :param str filename:
          :return: None.