Function toggleExpanded

toggleExpanded(
expanded: readonly string[],
key: string,
): { expanded: readonly string[]; isExpanded: boolean }
Toggle a node's expanded state.
Parameters
- expanded: readonly string[]
  Current expanded keys
- key: string
  Key to toggle
Returns { expanded: readonly string[]; isExpanded: boolean }
New expanded set and whether it's now expanded
- Defined in core/src/widgets/tree.ts:309