[Demonstration 1]

[Buggy Method]
@Test
public void retainAll() {
    list.retainAll(setOf(1, 3, 5));
    assertThat(list, equalTo(listOf(1, 3)));
}

[Buggy Hunk]
assertThat(list, equalTo(listOf(1, 3)));

[Patch]
isEqualToList(list, listOf(1, 3));

[Demonstration 2]

[Buggy Method]
@Test
public void testVenn3() {
    AbstractContour a = new AbstractContour("A");
    AbstractContour b = new AbstractContour("B");
    AbstractContour c = new AbstractContour("C");
    Circle2D circleA = new Circle2D(new Point2D(-5, 0), 7.0);
    Circle2D circleB = new Circle2D(new Point2D(-5, 0), 7.0);
    Circle2D circleC = new Circle2D(new Point2D(0, 5), 7.0);
    ConcreteCircle ca = new ConcreteCircle(a, circleA);
    ConcreteCircle cb = new ConcreteCircle(b, circleB);
    ConcreteCircle cc = new ConcreteCircle(c, circleC);
    AbstractDiagram ad = new AbstractDiagram(new HashSet<>(Arrays.asList(a, b, c)));
    ConcreteDiagram d = new ConcreteDiagram(ad, Arrays.asList(ca, cb, cc));
    ConcreteZoneIterator czvi = new ConcreteZoneIterator(Arrays.asList(ca, cb, cc));
    int size = 0;
    while (czvi.hasNext()) {
        czvi.next();
        size++;
    }
    assertThat(size, is(7));
}

[Buggy Hunk]
Circle2D circleB = new Circle2D(new Point2D(-5, 0), 7.0);

[Patch]
Circle2D circleB = new Circle2D(new Point2D(5, 0), 7.0);

[Demonstration 3]

[Buggy Method]
public static void assertSimpleTSOutput(TokenStream stream, String[] expected) throws IOException {
    stream.reset();
    CharTermAttribute termAttr = stream.getAttribute(CharTermAttribute.class);
    assertThat(termAttr, notNullValue());
    int i = 0;
    while (stream.incrementToken()) {
        assertThat(expected.length, greaterThan(i));
        assertThat("expected different term at index " + i, expected[i++], equalTo(termAttr.toString()));
    }
    assertThat("not all tokens produced", i, equalTo(expected.length));
}

[Buggy Hunk]
assertThat( "expected different term at index " + i, expected[i++], equalTo(termAttr.toString()));

[Patch]
assertThat("expected different term at index " + i, termAttr.toString(), equalTo(expected[i++]));