code: Observable<ChatConversationBase> getConversation(@NonNull String conversationId) {
  
          return Observable.create(emitter -> storeFactory.execute(new StoreTransaction<ChatStore>() {
              @Override
              protected void execute(ChatStore store) {
                  store.open();
                  ChatConversationBase c = store.getConversation(conversationId);
                  store.close();
                  emitter.onNext(c);
                  emitter.onCompleted();
              }
          }), Emitter.BackpressureMode.BUFFER);
      }
docs: Get single conversations from store implementation as an Observable.
  
  @return Observable returning single conversation from store.