Set possibleFutures = (Set)modMap.get(historyContext);
Set possibleFutures = (Set)modNonterminalMap.get(historyContext);
  private Set possibleFutures(ModifierEvent modEvent, boolean side) {    ProbabilityStructure modPS = modNonterminalPS;    int lastLevel = modNonterminalPSLastLevel;    boolean onLeft = side == Constants.LEFT;    Map modMap = (onLeft ? leftModNonterminalMap : rightModNonterminalMap);    Event historyContext = modPS.getHistory(modEvent, lastLevel);    Set possibleFutures = (Set)modMap.get(historyContext);    return possibleFutures;  }