LoroCounter cannot go inside a Container?

[canadaduane]

I'm trying to understand if I've made a mistake here, or if the library does not yet support LoroCounter inside a map:

// sandbox.ts
import { LoroCounter, LoroMap, LoroText, type Container } from "loro-crdt";

export function createItem(label: string, checked: boolean) {
  const item = new LoroMap<Record<string, Container>>();

  const $label = new LoroText();
  $label.insert(0, label);

  const $checked = new LoroCounter();
  if (checked) $checked.increment(1);

  item.setContainer("label", $label);
  item.setContainer("checked", $checked);

  return item;
}

const item = createItem("hello", true);

console.log(item.get("label").toString());
console.log(item.get("checked").value);

Typescript reports:

ts: Argument of type 'LoroCounter' is not assignable to parameter of type 'Container'.
  Type 'LoroCounter' is missing the following properties from type 'LoroMovableList<unknown>': getCursor, toArray, insertContainer, pushContainer, and 17 more.

And when I run the script, I get the following runtime error:

$ bun sandbox.ts
error: No kind method found or not a function
No kind method found or not a function

Bun v1.1.43 (Linux x64)