func (c *Connection) debugMsg(d debugMsg, args ...any) {
	if debugPrint {
		fmt.Println("debug: sending message", d, args)
	}

	switch d {
	case debugShutdown:
		c.updateState(StateShutdown)
	case debugKillInbound:
		c.connMu.Lock()
		defer c.connMu.Unlock()
		if c.debugInConn != nil {
			if debugPrint {
				fmt.Println("debug: closing inbound connection")
			}
			c.debugInConn.Close()
		}