[Demonstration 1]

[Buggy Method]
@Test
public void resetData_withDuplicatePersons_throwsAssertionError() {
    // Repeat ALICE twice
    List<Person> newPersons = Arrays.asList(new Person(ALICE), new Person(ALICE));
    List<Tag> newTags = new ArrayList<>(ALICE.getTags());
    List<Event> newEvents = Arrays.asList(new Event(Event1), new Event(Event2));
    AddressBookStub newData = new AddressBookStub(newPersons, newEvents, newTags);
    thrown.expect(AssertionError.class);
    addressBook.resetData(newData);
}

[Buggy Hunk]
List<Event> newEvents = Arrays.asList(new Event(Event1), new Event(Event2));

[Patch]
List<Event> newEvents = Arrays.asList(new Event(EVENT1), new Event(EVENT2));

[Demonstration 2]

[Buggy Method]
private void generateEvents() {
    clearEvents();
    Call<List<Event>> call = ServiceGenerator.create().getFutureEvents();
    call.enqueue(new Callback<List<Event>>() {

        @Override
        public void onResponse(@NonNull Call<List<Event>> call, @NonNull Response<List<Event>> response) {
            if (response.isSuccessful()) {
                List<Event> events = response.body();
                Date atm = Calendar.getInstance().getTime();
                for (final Event event : events) {
                    if (event.getDateEnd().getTime() > atm.getTime()) {
                        if (filter_club_id != null) {
                            if (filter_club_id.equals(event.getAssociation())) {
                                addEventToAdapter(event);
                            }
                        } else {
                            addEventToAdapter(event);
                        }
                    }
                }
            } else {
                Toast.makeText(getContext(), "EventsFragment", Toast.LENGTH_LONG).show();
            }
            if (swipeRefreshLayout != null) {
                swipeRefreshLayout.setRefreshing(false);
            }
        }

        @Override
        public void onFailure(@NonNull Call<List<Event>> call, @NonNull Throwable t) {
            Toast.makeText(getContext(), "EventsFragment", Toast.LENGTH_LONG).show();
            if (swipeRefreshLayout != null) {
                swipeRefreshLayout.setRefreshing(false);
            }
        }
    });
}

[Buggy Hunk]
Toast.makeText(getContext(), "EventsFragment", Toast.LENGTH_LONG).show();

[Patch]
Toast.makeText(App.getAppContext(), "EventsFragment", Toast.LENGTH_LONG).show();

[Demonstration 3]

[Buggy Method]
public static Result service(String ownerName, String projectName, String service, boolean isAdvertise) throws IOException, UnsupportedOperationException, ServletException {
    if (!isSupportedService(service)) {
        return forbidden(String.format("Unsupported service: '%s'", service));
    }
    Project project = Project.findByOwnerAndProjectName(ownerName, projectName);
    if (project == null) {
        return notFound();
    }
    models.User user = UserApp.currentUser();
    if (!isAllowed(project, service)) {
        if (user.isAnonymous()) {
            return BasicAuthAction.unauthorized(response());
        } else {
            // If you want the Git client showing your custom message to
            // the user, the Content-Type should be exact "text/plain"
            // without any parameter. For more details, see the code at
            // https://github.com/git/git/commit/426e70d4a11ce3b4f70636d57c6a0ab16ae08a00#diff-eea0ad565ec5903a11b6023755d491cfR154
            response().setHeader("Content-Type", "text/plain");
            return forbidden(String.format("'%s' has no permission to '%s/%s'.", user.name, ownerName, projectName));
        }
    }
    if (isAdvertise) {
        return ok(RepositoryService.gitAdvertise(project, service, response()));
    } else {
        if (request().body().isMaxSizeExceeded()) {
            return status(REQUEST_ENTITY_TOO_LARGE);
        } else {
            user.visits(project);
            return ok(RepositoryService.gitRpc(project, service, request(), response()));
        }
    }
}

[Buggy Hunk]
user.name, ownerName, projectName));

[Patch]
user.loginId, ownerName, projectName));