persistable sclass TickerSequences is IntSize {
  settable S market; // e.g. "TRBUSDT"
  
  gettable new L<TickerSequence> tickers;
  
  void add(TickerSequence ticker) {
    tickers.add(ticker);
  }
  
  TickerSequence get(int i) { ret tickers.get(i); }
  
  void sort {
    sortInPlaceByCalculatedField(tickers, ->. startTime());
  }
  
  public int size() { ret tickers.size(); }
  
  toString {
    ret commaCombine(
      spaceCombine(
        n2(tickers, " ticker sequence"),
        empty(market) ? null : "for " + market),
      formatDouble1(toDays(totalTime())) + " days",
      n2(nPricePoints(), "price point")
    );
  }
  
  long nPricePoints() {
    ret longSum(map(tickers, t -> (long) t.size()));
  }
  
  long totalTime() {
    ret longSum(map(tickers, ticker -> { var tr = ticker.timeRange(); ret tr == null ? 0 : tr.length(); }));
  }
  
  void merge(double maximumGapSeconds default 120) {
    sort();
    
    for (int i = 0; i+1 < l(tickers); i++) {
      var t1 = tickers.get(i);
      var t2 = tickers.get(i+1);
      if (t2.startTime()-t1.endTime() <= fromSeconds(maximumGapSeconds)) {
        t1.add(t2);
        tickers.remove(i+1);
        --i;
      }
    }
  }
  
  double firstPrice() {
    var ticker = first(tickers);
    ret ticker == null ? Double.NaN : ticker.firstPrice();
  }
  
  ItIt<Double> prices() {
    ret nestedIterator(tickers, ticker -> ticker.prices.iterator());
  }
  
    
  long startTime() { ret empty(tickers) ? null : first(tickers).startTime(); }
  long endTime() { ret empty(tickers) ? null : last(tickers).endTime(); }
  
  TickerSequence longest() {
    ret highestBy(tickers(), ticker -> duration(ticker.timeRange()));
  }
  
  TickerSequences mapTickers(IF1<TickerSequence> f) {
    new TickerSequences ts;
    for (t : tickers())
      ts.add(f.get(t));
    ret ts;
  }
  
  TickerSequences digitizeToPercent(double basePrice, double cellSizeInPercent) {
    ret mapTickers(ts -> ts.digitizeToPercent(basePrice, cellSizeInPercent));
  }
}