code: def swo_flush(self, num_bytes=None):
          
          if num_bytes is None:
              num_bytes = self.swo_num_bytes()
  
          buf = ctypes.c_uint32(num_bytes)
          res = self._dll.JLINKARM_SWO_Control(enums.JLinkSWOCommands.FLUSH,
                                               ctypes.byref(buf))
          if res < 0:
              raise errors.JLinkException(res)
  
          return None
docs: Flushes data from the SWO buffer.
  
          After this method is called, the flushed part of the SWO buffer is
          empty.
  
          If ``num_bytes`` is not present, flushes all data currently in the SWO
          buffer.
  
          Args:
            self (JLink): the ``JLink`` instance
            num_bytes (int): the number of bytes to flush
  
          Returns:
            ``None``
  
          Raises:
            JLinkException: on error