code: Observable<ComapiResult<MessageSentResponse>> doSendMessage(@NonNull final String token, @NonNull final String conversationId, @NonNull final MessageToSend message) {
          return wrapObservable(service.sendMessage(AuthManager.addAuthPrefix(token), apiSpaceId, conversationId, message).map(mapToComapiResult()), log, "Sending message to conversation " + conversationId);
      }
docs: Send message to the chanel.
  
  @param token          Comapi access token.
  @param conversationId ID of a conversation to send a message to.
  @param message        Message to be send.
  @return Observable to send message to a conversation.