[Demonstration 1]

[Buggy Method]
@FXML
public void onActionTxtDecimalPlacesChanged() {
    try {
        if (txtDecimalPlaces.textProperty().getValue().length() > 0 && txtDecimalPlaces.textProperty().getValue() != null) {
            config.setDecimalPlaces(Integer.parseInt(txtDecimalPlaces.textProperty().getValue()));
        }
    } catch (NumberFormatException e) {
        txtDecimalPlaces.textProperty().setValue(Integer.toString(config.getDecimalPlaces()));
        Alert alert = new Alert(AlertType.ERROR);
        alert.setTitle(Messages.SettingsDialogController_DialogNoNumber_Title);
        alert.setHeaderText(Messages.SettingsDialogController_6DialogNoNumber_Header);
        alert.setContentText(Messages.SettingsDialogController_DialogNoNumber_Content);
        alert.showAndWait();
    }
}

[Buggy Hunk]
alert.setHeaderText(Messages.SettingsDialogController_6DialogNoNumber_Header);

[Patch]
alert.setHeaderText(Messages.SettingsDialogController_DialogNoNumber_Header);

[Demonstration 2]

[Buggy Method]
@FXML
private void deleteSelectedPasswordEntry() {
    if (uictrlDatabaseEntryTable.getSelectionModel().getSelectedIndex() >= 0) {
        Alert alert = new Alert(AlertType.CONFIRMATION);
        alert.setTitle("Delete confirmation");
        alert.setHeaderText("Delete the selected password settings entry?");
        alert.setContentText("Are you sure you want to delete the password settings entry '" + dbEntry.getId() + "'? This action cannot be undone.");
        Optional<ButtonType> result = alert.showAndWait();
        if (result != null && result.get() == ButtonType.OK) {
            uictrlDatabaseEntryTable.getItems().remove(uictrlDatabaseEntryTable.getSelectionModel().getSelectedIndex());
            uictrlDatabaseEntryTable.getSelectionModel().clearSelection();
            dbEntry = null;
            mainApp.shouldSave = true;
        }
    }
}

[Buggy Hunk]
uictrlDatabaseEntryTable.getItems().remove(uictrlDatabaseEntryTable.getSelectionModel().getSelectedIndex());

[Patch]
items.remove(uictrlDatabaseEntryTable.getSelectionModel().getSelectedItem());

[Demonstration 3]

[Buggy Method]
@Override
public void create() {
    gameScreen = new GameScreen(Level.lvl_ward);
    showGameScreen();
}

[Buggy Hunk]
gameScreen = new GameScreen(Level.lvl_ward);

[Patch]
gameScreen = new GameScreen(Level.lvl_intro);