code: Observable<ComapiResult<ConversationDetails>> doUpdateConversation(@NonNull final String token, @NonNull final String conversationId, @NonNull final ConversationUpdate request, final String eTag) {
          return wrapObservable(!TextUtils.isEmpty(eTag) ? service.updateConversation(AuthManager.addAuthPrefix(token), eTag, apiSpaceId, conversationId, request).map(mapToComapiResult()) : service.updateConversation(AuthManager.addAuthPrefix(token), apiSpaceId, conversationId, request)
                  .map(mapToComapiResult()), log, "Updating conversation " + conversationId);
      }
docs: Returns observable to update a conversation.
  
  @param token          Comapi access token.
  @param eTag           Tag to specify local data version.
  @param conversationId ID of a conversation to update.
  @param request        Request with conversation details to update.
  @return Observable to update a conversation.