[Demonstration 1]

[Buggy Method]
@Override
public void onDelete() {
    if (Window.confirm("Are you sure you want to delete " + candidate.getName() + " ?")) {
        dispatch.execute(adminService.removeCandidate(candidate.getName()), new AdminRestCallback<Void>() {

            @Override
            public void onSuccess(Void result) {
                removeFromParentSlot();
            }
        });
    }
}

[Buggy Hunk]
dispatch.execute(adminService.removeCandidate(candidate.getName()), new AdminRestCallback<Void>() {

[Patch]
dispatch.execute(adminService.removeCandidate(candidate.getId()), new AdminRestCallback<Void>() {

[Demonstration 2]

[Buggy Method]
@Test
public void testDeleteContainerWithIncorrectDepthHeaderSet() {
    final String id = getRandomUniqueId();
    createObjectAndClose(id);
    HttpDelete httpDelete = deleteObjMethod(id);
    httpDelete.addHeader("Depth", "0");
    assertEquals(BAD_REQUEST.getStatusCode(), getStatus(httpDelete));
    assertNotDeleted(id);
}

[Buggy Hunk]
HttpDelete httpDelete = deleteObjMethod(id);

[Patch]
final HttpDelete httpDelete = deleteObjMethod(id);

[Demonstration 3]

[Buggy Method]
private void sedToServer(String name) {
    sedToServer.setDisable(true);
    try {
        HttpPost httpPost = new HttpPost("/api/languages");
        List<NameValuePair> params = new ArrayList<>();
        params.add(new BasicNameValuePair("language", name));
        params.add(new BasicNameValuePair("password", "secret"));
        httpPost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));
        HttpResponse httpResponse = httpClient.execute(server, httpPost);
        HttpEntity entity = httpResponse.getEntity();
        if (httpResponse.getStatusLine().getStatusCode() == 204)
            return;
        BufferedReader br = new BufferedReader(new InputStreamReader((entity.getContent())));
        String response = br.readLine();
        String error = new JsonParser().parse(response).getAsJsonObject().get("error").getAsString();
        System.out.println(error);
    } catch (HttpHostConnectException ignore) {
    } catch (IOException e) {
        e.printStackTrace();
    }
}

[Buggy Hunk]
String error = new JsonParser().parse(response).getAsJsonObject().get("error").getAsString();

[Patch]
JsonElement error = new JsonParser().parse(response).getAsJsonObject().get("error");