ReadOnlyObservableSet.add - Andrei15193/react-model-view-viewmodel GitHub Wiki

Ensures the provided item is in the set. There can be at most only one instance of an item in a set at any given time.

protected add(
  item: TItem
): this

Source reference: src/collections/observableSet/ReadOnlyObservableSet.ts:262.

• item: TItem
  The item to add to the set.

The observable set on which the operation is performed.

• Set.add