src/vs/workbench/api/common/extHostTypeConverters.ts/convertTestResultItem
	const convertTestResultItem = (item: SerializedTestResultItem, byInternalId: Map<string, SerializedTestResultItem>): vscode.TestResultSnapshot => ({
		...TestItem.toPlain(item.item),
		taskStates: item.tasks.map(t => ({
			state: t.state,
			duration: t.duration,
			messages: t.messages.map(TestMessage.to),
		})),
		children: item.children
			.map(c => byInternalId.get(c))
			.filter(isDefined)
			.map(c => convertTestResultItem(c, byInternalId)),
	});