code: public Observable<ComapiResult<ConversationDetails>> updateConversation(@NonNull final String conversationId, @NonNull final ConversationUpdate request, @Nullable final String eTag) {
  
          final String token = getToken();
  
          if (sessionController.isCreatingSession()) {
              return getTaskQueue().queueUpdateConversation(conversationId, request, eTag);
          } else if (TextUtils.isEmpty(token)) {
              return Observable.error(getSessionStateErrorDescription());
          } else {
              return doUpdateConversation(token, conversationId, request, eTag);
          }
      }
docs: Returns observable to update a conversation.
  
  @param conversationId ID of a conversation to update.
  @param request        Request with conversation details to update.
  @param eTag           Tag to specify local data version.
  @return Observable to update a conversation.