hasChildren() {
		for (let i = 0; i < this.nodes.length; i = i + 1) {
			const subnode = this.nodes[i];
			if (subnode.length > 0 || subnode.objects.length > 0) {
				return true;
			}
		}
		return false;
	}
return true if the node has any children
@returns {boolean} true if the node has any children