sclass PullbackToProfit {
  settable double pullback;
  settable double profit;
  settable long startTime;
  settable long timestamp;
  
  double cleanness() {
    ret profit() <= 0 ? 0 : profit()/pullback();
  }
  
  toString {
    var duration = formatMinutes(timestamp()-startTime());
    ret shortenNumbers(2, concat("Callback ", pullback(), "% yields ", profit(), "% profit in ", duration, " (cleanness ", formatDouble1(cleanness()), ")"));
  }
  
  bool replaces(PullbackToProfit ptp) {
    ret pullback() <= ptp.pullback()
      && profit() >= ptp.profit();
  }
}