code: def write_data(self, buf):
          
          if self.hid.write(buf) != len(buf):
              raise IOError(
                  'pywws.device_cython_hidapi.USBDevice.write_data failed')
          return True
docs: Send data to the device.
  
          :param buf: the data to send.
  
          :type buf: list(int)
  
          :return: success status.
  
          :rtype: bool