[Demonstration 1]

[Buggy Method]
@Test
public void whenDisconnected_onStart_startsConnecting() throws Exception {
    engine.disconnect();
    whileRetrievingMessagesDo(new Runnable() {

        @Override
        public void run() {
            assertThat(engine, isInState("Connecting"));
        }
    });
    engine.start();
    verify(chatClient).get();
}

[Buggy Hunk]
verify(chatClient).get();

[Patch]
verify(dataProvider).get();

[Demonstration 2]

[Buggy Method]
public String get_count_of_days(String Created_date_String, String Expire_date_String) {
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd", Locale.getDefault());
    Date Created_convertedDate = null, Expire_CovertedDate = null, todayWithZeroTime = null;
    try {
        Created_convertedDate = dateFormat.parse(Created_date_String);
        Expire_CovertedDate = dateFormat.parse(Expire_date_String);
        Date today = new Date();
        todayWithZeroTime = dateFormat.parse(dateFormat.format(today));
    } catch (ParseException e) {
        e.printStackTrace();
    }
    int c_year = 0, c_month = 0, c_day = 0;
    if (Created_convertedDate.after(todayWithZeroTime)) {
        Calendar c_cal = Calendar.getInstance();
        c_cal.setTime(Created_convertedDate);
        c_year = c_cal.get(Calendar.YEAR);
        c_month = c_cal.get(Calendar.MONTH);
        c_day = c_cal.get(Calendar.DAY_OF_MONTH);
    } else {
        Calendar c_cal = Calendar.getInstance();
        c_cal.setTime(todayWithZeroTime);
        c_year = c_cal.get(Calendar.YEAR);
        c_month = c_cal.get(Calendar.MONTH);
        c_day = c_cal.get(Calendar.DAY_OF_MONTH);
    }
    Calendar e_cal = Calendar.getInstance();
    e_cal.setTime(Expire_CovertedDate);
    int e_year = e_cal.get(Calendar.YEAR);
    int e_month = e_cal.get(Calendar.MONTH);
    int e_day = e_cal.get(Calendar.DAY_OF_MONTH);
    Calendar date1 = Calendar.getInstance();
    Calendar date2 = Calendar.getInstance();
    date1.clear();
    date1.set(c_year, c_month, c_day);
    date2.clear();
    date2.set(e_year, e_month, e_day);
    long diff = date1.getTimeInMillis() - date2.getTimeInMillis();
    float dayCount = (float) diff / (24 * 60 * 60 * 1000);
    return ("" + ((int) dayCount));
}

[Buggy Hunk]
return ("" + ((int) dayCount ));

[Patch]
return ("" + ((int) dayCount+1 ));

[Demonstration 3]

[Buggy Method]
protected void renderHeaderViews() {
    headerViews.clear();
    for (int columnIndex = 0; columnIndex < 4; columnIndex++) {
        View headerView = adapter.getHeaderView(columnIndex, this);
        headerViews.add(headerView);
    }
}

[Buggy Hunk]
for (int columnIndex = 0; columnIndex < 4; columnIndex++) {

[Patch]
for (int columnIndex = 0; columnIndex < adapter.getColumnCount(); columnIndex++) {