persistable sclass TickerSequence {
  new LongBuffer timestamps;
  new DoubleBuffer prices;
  
  void add(double price, long timestamp) {
    timestamps.add(timestamp);
    prices.add(price);
  }
  
  void add(double[] prices, long[] timestamps) {
    assertEquals(l(prices()), l(timestamps));
    this.prices.addAll(asList(prices));
    this.timestamps.addAll(asList(timestamps));
  }
  
  toString {
    ret "TickerSequence length " + n2(l(prices));
  }
}