[Demonstration 1]

[Buggy Method]
public static Cipher getInstance(Cipher.TYPE ciphertype, CipherSettings settings) throws Exception {
    Algorithm usedAlgo = CipherFactory.determineAlgorithm(ciphertype, settings);
    switch(ciphertype) {
        case AES:
            return new AES(usedAlgo, settings);
        case DES:
            return new DES(new AlgoDES());
        default:
            return null;
    }
}

[Buggy Hunk]
return new DES(new AlgoDES());

[Patch]
return new DES(new AlgoDES(), settings);

[Demonstration 2]

[Buggy Method]
@Override
public void onResponse(Call<BaseResponse<UserTransaction>> call, Response<BaseResponse<UserTransaction>> response) {
    if (response.body() != null) {
        try {
            WritableMap responseMap = ModelConverterUtils.convertJsonToMap(new JSONObject(new Gson().toJson(response.body().data, UserTransaction.class)));
            promise.resolve(response);
        } catch (JSONException e) {
            e.printStackTrace();
            promise.reject("", e);
        }
    } else {
        try {
            promise.reject("", response.errorBody().string());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

[Buggy Hunk]
promise.resolve(response);

[Patch]
promise.resolve(responseMap);

[Demonstration 3]

[Buggy Method]
public String getUsernameFromToken(String token) {
    String username;
    try {
        final Claims claims = getClaimsFromToken(token);
        username = claims.getSubject();
    } catch (Exception e) {
        username = null;
    }
    return username;
}

[Buggy Hunk]
} catch (Exception e) {

[Patch]
} catch (NullPointerException e) {