persistable class Position extends G22TradingStrategy.Position {

    settable AbstractJuicer juicer;

    toString {

      ret super.toString()

        + (juicer == null ? "" : ". " + commaCombine(juicer.currentSignals()));

    }

  }

  srecord ProfitBeforeLeverageJuiceable(Position p) is Juiceable {

    public double juiceValue() { ret p.profitBeforeLeverage(); }

  }

  void juiceStrategy_price(double price) {

    if (currentPrice == price) ret;

    currentPrice = price;

    afterwards { afterStep(); change(); }

    juiceStrategy_newPrice(price);

  }

  void juiceStrategy_newPrice(double price) {

    for (p : openPositions()) {

      cast p to Position;

      if (p.juicer != null) {

        var signals = p.juicer.calculateCloseSignals();

        var strongest = highestBy(signals, s -> s.strength());

        if (strongest != null && strongest.isTrigger()) {

          p.close(strongest);

        }

      }

    }

  }

  Position openShort() { ret openPosition(-1); }

  Position openLong() { ret openPosition(1); }

  Position openPosition(int direction, O openReason default null) {

    new Position p;

    p.marginToUse = marginToUseForNewPosition();

    addJuicer(p);

    ret openPosition(p, direction, openReason);

  }

  void addJuicer(Position p) {

    var j = makeJuicer();

    if (j == null) ret;

    j.copyTransientValuesFrom(p.juicer);

    j.juiceable(new ProfitBeforeLeverageJuiceable(p));

    p.juicer(j);

  }

  void recreateJuicersForExistingPositions aka updateJuicers() {

    for (p : openPositions()) {

      cast p to Position;

      addJuicer(p);

    }

  }

  L<? extends Position> openPositions() { ret (L) super.openPositions(); }

  L<AbstractJuicer> allJuicers aka juicers() {

    ret map(openPositions(), -> .juicer());

  }