[Demonstration 1]

[Buggy Method]
private boolean doAsyncConnectionTask(String method, ToDo todo) {
    boolean result = true;
    try {
        String url = URL;
        if (method.equals("PUT") || method.equals("DELETE"))
            url += todo.getDbId();
        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        connection.setConnectTimeout(5000);
        connection.setRequestProperty("Content-Type", "application/json");
        connection.setRequestMethod(method);
        if (method.equals("POST") || method.equals("PUT")) {
            connection.setDoOutput(true);
            OutputStream outputStream = connection.getOutputStream();
            ObjectMapper mapper = new ObjectMapper();
            mapper.writeValue(outputStream, todo);
        }
        InputStream inputStream = connection.getInputStream();
        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            result = false;
        }
        if (method.equals("GET")) {
            todoList.clear();
            ObjectMapper mapper = new ObjectMapper();
            JsonNode rootNode = mapper.readValue(inputStream, JsonNode.class);
            for (JsonNode node : rootNode) {
                todoList.add(mapper.treeToValue(node, ToDo.class));
            }
        }
        connection.disconnect();
    } catch (IOException e) {
        result = false;
    }
    return result;
}

[Buggy Hunk]
if (method.equals("PUT") || method.equals("DELETE"))

[Patch]
if (todo != null && (method.equals("PUT") || method.equals("DELETE")))

[Demonstration 2]

[Buggy Method]
@RequestMapping(method = RequestMethod.POST, value = "/register")
public Callable register(@RequestBody @Valid User user) {
    return () -> {
        userService.register(user);
        return new ResponseEntity<>(HttpStatus.CREATED);
    };
}

[Buggy Hunk]
return new ResponseEntity<>(HttpStatus.CREATED);

[Patch]
return new LDResponseEntity<>(HttpStatus.CREATED);

[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));