code: def rtt_get_num_up_buffers(self):
          
          cmd = enums.JLinkRTTCommand.GETNUMBUF
          dir = ctypes.c_int(enums.JLinkRTTDirection.UP)
          return self.rtt_control(cmd, dir)
docs: After starting RTT, get the current number of up buffers.
          Args:
            self (JLink): the ``JLink`` instance
  
          Returns:
            The number of configured up buffers on the target.
  
          Raises:
            JLinkRTTException if the underlying JLINK_RTTERMINAL_Control call fails.