@class NSArray, NSMutableArray, NSMutableDictionary; @interface _WGConcreteDataSource : NSObject { NSMutableArray *_observers; NSMutableDictionary *_identifiersToData; } @property (readonly, nonatomic) NSArray *dataIdentifiers; @property (readonly, nonatomic) NSArray *data; - (void)dataSource:(id)a0 replaceWithDatum:(id)a1 observerUpdateBlock:(id /* block */)a2; - (id)init; - (id)datumWithIdentifier:(id)a0; - (void)addObserver:(id)a0 completion:(id /* block */)a1; - (void).cxx_destruct; - (void)removeObserver:(id)a0 completion:(id /* block */)a1; - (void)dataSource:(id)a0 removeDatumWithIdentifier:(id)a1 observerUpdateBlock:(id /* block */)a2; @end