[Demonstration 1]

[Buggy Method]
@Override
public CommandResult execute() {
    if (checkDate == "") {
        model.updateFilteredListToShowAll();
        return new CommandResult(MESSAGE_SUCCESS);
    } else {
        model.updateFilteredTaskList(checkDate, preposition);
        return new CommandResult(getMessageForTaskListShownSummary(model.getFilteredTaskList().size()));
    }
}

[Buggy Hunk]
if(checkDate == "") {

[Patch]
if("".equals(checkDate)) {

[Demonstration 2]

[Buggy Method]
private Consumer<String> setSortingOrder(Prefix prefix) {
    return s -> {
        sortType = prefix.toString();
        if (s.equals(SortCommand.BY_ASCENDING)) {
            isDescending = new Boolean(false);
            return;
        }
        //Defaults to ascending when order not specified
        if (s.equals("")) {
            isDescending = new Boolean(false);
            return;
        }
        if (s.equals(SortCommand.BY_DESCENDING)) {
            isDescending = new Boolean(true);
            return;
        }
    };
}

[Buggy Hunk]
if (s.equals("")) {

[Patch]
if ("".equals(s)) {