code: Observable<List<ChatConversationBase>> loadAllConversations() {
  
          return Observable.create(emitter -> storeFactory.execute(new StoreTransaction<ChatStore>() {
              @Override
              protected void execute(ChatStore store) {
                  store.open();
                  List<ChatConversationBase> conversations = store.getAllConversations();
                  store.close();
                  emitter.onNext(conversations);
                  emitter.onCompleted();
              }
          }), Emitter.BackpressureMode.LATEST);
      }
docs: Wraps loading all conversations from store implementation into an Observable.
  
  @return Observable returning all conversations from store.