persistable abstract sclass AbstractJuicer extends MetaWithChangeListeners {
  // what we are monitoring & closing (a position or a strategy)
  settableWithVar Juiceable juiceable;
  
  settableWithVar double juiceValue;
  
  // last calculated signals
  settableWithVar L<SignalWithStrength> currentSignals;
  
  event calculatingCloseSignals(L<SignalWithStrength> outList);
  
  // must return a new list
  swappable L<SignalWithStrength> calculateCloseSignals() {
    grabJuiceValue();
    new L<SignalWithStrength> signals;
    calculatingCloseSignals(signals);
    currentSignals(signals);
    ret signals;
  }
  
  void grabJuiceValue {
    juiceValue(juiceable.juiceValue());
  }
  
  selfType configClone() {
    ret restructure(this);
  }
  
  void copyTransientValuesFrom(AbstractJuicer juicer) {}
}