function check_nodes_for_namespace(nodes, namespace) {
	/**
	 * @param {AST.SvelteElement | AST.RegularElement} node}
	 * @param {{stop: () => void}} context
	 */
	const RegularElement = (node, { stop }) => {
		if (!node.metadata.svg && !node.metadata.mathml) {
			namespace = 'html';
			stop();
		} else if (namespace === 'keep') {
			namespace = node.metadata.svg ? 'svg' : 'mathml';
		}
	};

	for (const node of nodes) {
		walk(
			node,
			{},
			{
				_(node, { next }) {
					if (
						node.type === 'EachBlock' ||
						node.type === 'IfBlock' ||
						node.type === 'AwaitBlock' ||
						node.type === 'Fragment' ||
						node.type === 'KeyBlock' ||
						node.type === 'RegularElement' ||
						node.type === 'SvelteElement' ||
						node.type === 'Text'
					) {
						next();
					}
				},
				SvelteElement: RegularElement,
				RegularElement,
				Text(node) {
					if (node.data.trim() !== '') {
						namespace = 'maybe_html';
					}
				}
			}
		);

		if (namespace === 'html') return namespace;
	}

	return namespace;
}
Heuristic: Keep current namespace, unless we find a regular element,
in which case we always want html, or we only find svg nodes,
in which case we assume svg.
@param {AST.SvelteNode[]} nodes
@param {Namespace | 'keep' | 'maybe_html'} namespace