Program: 19711
Project: 19711
Buggy source:
@Override protected Tuple<InteractionResult,Double> interactWithOtherGroups(){
  double currentFoodReserve=getDataModel().getCurrentReservedFood();
  Tuple<InteractionResult,Double> interactionResult=new Tuple<InteractionResult,Double>();
  System.out.println("String_Node_Str");
  System.out.println(this.getDataModel().getName());
  System.out.println("String_Node_Str" + this.getDataModel().getCurrentReservedFood());
  System.out.println("String_Node_Str" + inNeed.size() + "String_Node_Str");
  for (  String s : inNeed.keySet()) {
    if (getConn().getGroupById(s) != null)     System.out.println("String_Node_Str" + getConn().getGroupById(s).getName() + "String_Node_Str"+ inNeed.get(s)+ "String_Node_Str");
  }
  if (inNeed.containsKey(this.getId())) {
    if (currentFoodReserve > priceToPlay + 50) {
      inNeed.remove(this.getId());
      System.out.println("String_Node_Str");
      interactionResult.add(InteractionResult.NothingHappened,0.0);
    }
 else     if (loanRequestsAccepted.containsKey(this.getId())) {
      HashMap<String,Tuple<Double,Double>> loanRecord=loanRequestsAccepted.get(this.getId());
      Set<String> giverID=loanRecord.keySet();
      this.loansTaken.put(giverID.iterator().next(),loanRecord.get(giverID.iterator().next()));
      loanRequestsAccepted.remove(this.getId());
      inNeed.remove(this.getId());
      System.out.println("String_Node_Str" + interactionResult.getKey() + "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
      System.out.println("String_Node_Str" + getDataModel().getCurrentReservedFood());
      interactionResult.add(InteractionResult.LoanTaken,loanRecord.get(giverID.iterator().next()).getKey());
    }
 else {
      interactionResult.add(InteractionResult.NothingHappened,0.0);
      System.out.println("String_Node_Str" + interactionResult.getKey() + "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
    }
    return interactionResult;
  }
  if (!inNeed.isEmpty()) {
    for (    String groupID : inNeed.keySet()) {
      if (loanRequestsAccepted.containsKey(groupID))       break;
      double amountNeeded=inNeed.get(groupID);
      double interestRate=0.15;
      if (currentFoodReserve - amountNeeded > priceToPlay + 50) {
        Tuple<Double,Double> loanInfo=new Tuple<Double,Double>();
        loanInfo.add(amountNeeded,interestRate);
        this.loansGiven.put(groupID,loanInfo);
        HashMap<String,Tuple<Double,Double>> loanRecord=new HashMap<String,Tuple<Double,Double>>();
        loanRecord.put(this.getId(),loanInfo);
        loanRequestsAccepted.put(groupID,loanRecord);
        interactionResult.add(InteractionResult.LoanGiven,amountNeeded);
        System.out.println(getConn().getGroupById(groupID).getName() + "String_Node_Str" + interactionResult.getKey()+ "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
        System.out.println("String_Node_Str" + getDataModel().getCurrentReservedFood());
        return interactionResult;
      }
    }
  }
  interactionResult.add(InteractionResult.NothingHappened,0.0);
  System.out.println("String_Node_Str");
  return interactionResult;
}

Fixed version (ground truth):
@Override protected Tuple<InteractionResult,Double> interactWithOtherGroups(){
  double currentFoodReserve=getDataModel().getCurrentReservedFood();
  Tuple<InteractionResult,Double> interactionResult=new Tuple<InteractionResult,Double>();
  System.out.println("String_Node_Str");
  System.out.println(this.getDataModel().getName());
  System.out.println("String_Node_Str" + this.getDataModel().getCurrentReservedFood());
  System.out.println("String_Node_Str" + inNeed.size() + "String_Node_Str");
  for (  String s : inNeed.keySet()) {
    if (getConn().getGroupById(s) != null)     System.out.println("String_Node_Str" + getConn().getGroupById(s).getName() + "String_Node_Str"+ inNeed.get(s)+ "String_Node_Str");
  }
  if (inNeed.containsKey(this.getId())) {
    if (currentFoodReserve > priceToPlay + 50) {
      inNeed.remove(this.getId());
      System.out.println("String_Node_Str");
      interactionResult.add(InteractionResult.NothingHappened,0.0);
    }
 else     if (loanRequestsAccepted.containsKey(this.getId())) {
      HashMap<String,Tuple<Double,Double>> loanRecord=loanRequestsAccepted.get(this.getId());
      Set<String> giverID=loanRecord.keySet();
      this.loansTaken.put(giverID.iterator().next(),loanRecord.get(giverID.iterator().next()));
      loanRequestsAccepted.remove(this.getId());
      inNeed.remove(this.getId());
      interactionResult.add(InteractionResult.LoanTaken,loanRecord.get(giverID.iterator().next()).getKey());
      System.out.println("String_Node_Str" + interactionResult.getKey() + "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
      System.out.println("String_Node_Str" + getDataModel().getCurrentReservedFood());
    }
 else {
      interactionResult.add(InteractionResult.NothingHappened,0.0);
      System.out.println("String_Node_Str" + interactionResult.getKey() + "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
    }
    return interactionResult;
  }
  if (!inNeed.isEmpty()) {
    for (    String groupID : inNeed.keySet()) {
      if (loanRequestsAccepted.containsKey(groupID))       break;
      double amountNeeded=inNeed.get(groupID);
      double interestRate=0.15;
      if (currentFoodReserve - amountNeeded > priceToPlay + 50) {
        Tuple<Double,Double> loanInfo=new Tuple<Double,Double>();
        loanInfo.add(amountNeeded,interestRate);
        this.loansGiven.put(groupID,loanInfo);
        HashMap<String,Tuple<Double,Double>> loanRecord=new HashMap<String,Tuple<Double,Double>>();
        loanRecord.put(this.getId(),loanInfo);
        loanRequestsAccepted.put(groupID,loanRecord);
        interactionResult.add(InteractionResult.LoanGiven,amountNeeded);
        System.out.println(getConn().getGroupById(groupID).getName() + "String_Node_Str" + interactionResult.getKey()+ "String_Node_Str"+ interactionResult.getValue()+ "String_Node_Str");
        System.out.println("String_Node_Str" + getDataModel().getCurrentReservedFood());
        return interactionResult;
      }
    }
  }
  interactionResult.add(InteractionResult.NothingHappened,0.0);
  System.out.println("String_Node_Str");
  return interactionResult;
}