code: func (h *handler) handleImmediate(msg *jsonrpcMessage) bool {
  	start := time.Now()
  	switch {
  	case msg.isNotification():
  		if strings.HasSuffix(msg.Method, notificationMethodSuffix) {
  			h.handleSubscriptionResult(msg)
  			return true
  		}
  		return false
  	case msg.isResponse():
  		h.handleResponse(msg)
  		h.log.Trace("Handled RPC response", "reqid", idForLog{msg.ID}, "t", time.Since(start))
  		return true
  	default:
  		return false
  	}
  }
docs: // handleImmediate executes non-call messages. It returns false if the message is a
  // call or requires a reply.