[Demonstration 1]

[Buggy Method]
public void setDate(String date) {
    this.date = date;
    if (date == null) {
        this.date = "";
    }
    DateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz");
    try {
        this.date2 = formatter.parse(date);
    } catch (ParseException e) {
        this.date2 = null;
    }
}

[Buggy Hunk]
DateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz");

[Patch]
DateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss Z", Locale.ENGLISH);

[Demonstration 2]

[Buggy Method]
public JsonObject getByIdJson(int id) {
    Message m = getById(id);
    if (m != null) {
        return getById(id).toJson();
    } else {
        return null;
    }
}

[Buggy Hunk]
return getById(id).toJson();

[Patch]
return getById(id).toJSON();