Function index

index<TObject, TKeys>(iterable, ...keys): NestedInternMap<TObject, TObject, TKeys>
Equivalent to group but returns a unique value per compound key instead of an array, throwing if the key is not unique.
Type Parameters
- TObject
- TKeys extends unknown[]
Parameters
- iterable: Iterable<TObject>
  The iterable to group.
- Rest ...keys: {
  [Index in string | number | symbol]: ((value, index, values) => TKeys[Index])
  }
Returns NestedInternMap<TObject, TObject, TKeys>