code: def _strip_rtap(frame):
          
          rtap_len = WiHelper.__get_rtap_len(frame)
          rtap = frame[:rtap_len]
          packet = frame[rtap_len:]
          return rtap, packet
docs: strip injected radiotap header.
          :return: ctypes.Structure
              radiotap header
          :return: ctypes.Structure
              actual layer 2 Wi-Fi payload