code: void queryMissingEvents(String conversationId, long from, int limit) {
          obsExec.execute(checkState().flatMap(client -> client.service().messaging().queryConversationEvents(conversationId, from, limit))
                  .flatMap((result) -> processEventsQueryResponse(result, new ArrayList<>())));
      }
docs: Query missing events as {@link com.comapi.chat.internal.MissingEventsTracker} reported.
  
  @param conversationId Unique id of a conversation.
  @param from           Conversation event id to start from.
  @param limit          Limit of events in a query.