getDataStream(dataInfo: DataInfo): Observable<any>;
getDataStream<T>(dataInfo: DataInfo): Observable<T>;
getDataStream<T>(dataInfo: DataInfo): Observable<T> {
dataChanged(dataInfo: DataInfo | DataInfo[]): any{
clear(): Observable<any>{
removeItems(items: DataInfo[]): Observable<any>
applyValidity(dataItems: { dataInfo: DataInfo; validDate: Date }[])
addItem(dataItmes: { dataInfo: DataInfo; data: any }[]): Observable<any>
If you want to provide your class as **DATA_STORAGE** and **DATA_PROVIDER** be careful to provide
it with **useExisting** to have one instance for them.
useExisting: MyDataStorage,
useExisting: MyDataStorage,