[Demonstration 1]

[Buggy Method]
public synchronized void clear() {
    timeElapsed = 0;
    //      neededTimeStep = 0.5;
    //      timeStep = 0.5;
    getPointMasses().clear();
}

[Buggy Hunk]
getPointMasses().clear();

[Patch]
pointMasses.clear();

[Demonstration 2]

[Buggy Method]
private void printElementData(String aKey, String aFormat, StringBuilder aString) {
    // print all data in map
    if (aKey.equals("all") || aKey.equals("All")) {
        // print data for all elements in map
        for (Map.Entry<String, List<String>> element : elementMap.entrySet()) {
            // define map variables
            String key = element.getKey();
            List<String> tempList = element.getValue();
            // print element data
            System.out.printf(aFormat, key, tempList.get(0), tempList.get(1), tempList.get(2));
        }
    } else {
        // print specific element data
        if (this.elementMap.get(aKey) != null) {
            // create temporary list for element data
            List<String> tempList = this.elementMap.get(aKey);
            // print element data
            System.out.printf(aFormat, aKey, tempList.get(1), tempList.get(0), tempList.get(2));
        } else {
            // add input key to 'not found' string
            aString.append(aKey);
            aString.append(" ");
        }
    }
}

[Buggy Hunk]
System.out.printf(aFormat, aKey, tempList.get(1), tempList.get(0), tempList.get(2));

[Patch]
System.out.printf(aFormat, aKey, tempList.get(0), tempList.get(1), tempList.get(2));

[Demonstration 3]

[Buggy Method]
protected IfcModelInterface mergeScales(Project project, Set<IfcModelInterface> ifcModels, ModelHelper modelHelper) throws MergeException {
    long size = 0;
    PackageMetaData packageMetaData = null;
    for (IfcModelInterface ifcModel : ifcModels) {
        size += ifcModel.size();
        packageMetaData = ifcModel.getPackageMetaData();
    }
    IfcModelInterface endModel = new BasicIfcModel(packageMetaData, null, (int) size);
    modelHelper.setTargetModel(endModel);
    modelHelper.setObjectFactory(endModel);
    modelHelper.setKeepOriginalOids(true);
    float foundPrefix = Float.MIN_VALUE;
    boolean allModelsSameScale = allModelsSameScale(ifcModels, foundPrefix);
    if (allModelsSameScale) {
        for (IfcModelInterface ifcModel : ifcModels) {
            for (long key : ifcModel.keySet()) {
                IdEObject ideObject = (IdEObject) ifcModel.get(key);
                if (ideObject instanceof IfcRoot) {
                    String name = ((IfcRoot) ideObject).getName();
                    if (name != null && name.equalsIgnoreCase("dummy"))
                        continue;
                }
                try {
                    modelHelper.copy(ideObject, true);
                } catch (IfcModelInterfaceException e) {
                    throw new MergeException(e);
                }
            }
        }
    } else {
        endModel.setUseDoubleStrings(false);
        SIPrefix prefix = project.getExportLengthMeasurePrefix();
        for (IfcModelInterface ifcModel : ifcModels) {
            float scale = (float) (getLengthUnitPrefix(ifcModel) / Math.pow(10.0, prefix.getValue()));
            setLengthUnitMeasure(ifcModel, prefix);
            ifcModel.indexGuids();
            Scaler scaler = new Scaler(ifcModel);
            scaler.scale(scale);
            for (long key : ifcModel.keySet()) {
                try {
                    modelHelper.copy((IdEObject) ifcModel.get(key), true);
                } catch (IfcModelInterfaceException e) {
                    throw new MergeException(e);
                }
            }
        }
    }
    return endModel;
}

[Buggy Hunk]
for (long key : ifcModel.keySet()) {

[Patch]
for (long key : new HashSet<>(ifcModel.keySet())) {