src/vs/base/common/map.ts/TernarySearchTree/_entries
class TernarySearchTree:	private *_entries(node: TernarySearchTreeNode<K, V> | undefined): IterableIterator<[K, V]> {
		// DFS
		if (!node) {
			return;
		}
		const stack = [node];
		while (stack.length > 0) {
			const node = stack.pop();
			if (node) {
				if (node.value) {
					yield [node.key, node.value];
				}
				if (node.left) {
					stack.push(node.left);
				}
				if (node.mid) {
					stack.push(node.mid);
				}
				if (node.right) {
					stack.push(node.right);
				}
			}
		}
	}