API Reference > presentation-common > Core > KeySet > add add Method Add a key or keys to this KeySet. add(value: Keys | Key, pred?: (key: Key) => boolean): KeySet Parameter Type Description value Keys | Key A key or keys to add. pred (key: Key) => boolean An optional predicate function that indicates whether a key should be added Returns - KeySet itself Defined in presentation/common/src/KeySet.ts Line 192 Last Updated: 13 June, 2024