function validate_block_not_empty(node, context) {
	if (!node) return;
	// Assumption: If the block has zero elements, someone's in the middle of typing it out,
	// so don't warn in that case because it would be distracting.
	if (node.nodes.length === 1 && node.nodes[0].type === 'Text' && !node.nodes[0].raw.trim()) {
		w.block_empty(node.nodes[0]);
	}
}
@param {AST.Fragment | null | undefined} node
@param {Context} context