Function usePersistedKeys

packages/react-aria-components/src/Collection.tsx:291–293

(focusedKey: Key | null)

type PersistedKeysReturnValue = Set<Key> | null;
export function usePersistedKeys(focusedKey: Key | null): PersistedKeysReturnValue {
  return useMemo(() => (focusedKey != null ? new Set([focusedKey]) : null), [focusedKey]);
}