The list of features as an enum to uniquely type each HydrationFeature.
HydrationFeature
enum HydrationFeatureKind { NoHttpTransferCache: HydrationFeatureKind.NoHttpTransferCache; HttpTransferCacheOptions: HydrationFeatureKind.HttpTransferCacheOptions; I18nSupport: HydrationFeatureKind.I18nSupport; EventReplay: HydrationFeatureKind.EventReplay; IncrementalHydration: HydrationFeatureKind.IncrementalHydration; NoIncrementalHydration: HydrationFeatureKind.NoIncrementalHydration;}