// we can't send data frames on the root stream (only control frames).
	if n.id != 0 {
		openParent = openParent || (n.state == http2priorityNodeOpen)
	}

	// Common case: only one kid or all kids have the same weight.
	// Some clients don't use weights; other clients (like web browsers)
	// use mostly-linear priority trees.
	w := n.kids.weight
	needSort := false