code: public Observable<ComapiResult<MessagesQueryResponse>> queryMessages(@NonNull final String conversationId, final Long from, @NonNull final Integer limit) {
  
          final String token = getToken();
  
          if (sessionController.isCreatingSession()) {
              return getTaskQueue().queueQueryMessages(conversationId, from, limit);
          } else if (TextUtils.isEmpty(token)) {
              return Observable.error(getSessionStateErrorDescription());
          } else {
              return doQueryMessages(token, conversationId, from, limit);
          }
      }
docs: Query chanel messages.
  
  @param conversationId ID of a conversation to query messages in it.
  @param from           ID of the message to start from.
  @param limit          Limit of events to obtain in this call.
  @return Observable to get messages in a conversation.