[Demonstration 1]

[Buggy Method]
public Object get(Object key) {
    Entry result = (Entry) super.get(key);
    if (result != null) {
        if (!result.isActive()) {
            remove(key);
            result = null;
        }
    }
    return result;
}

[Buggy Hunk]
Entry result = (Entry) super.get(key);

[Patch]
er.extensions.components.ERXCachingWrapper.Entry result = (er.extensions.components.ERXCachingWrapper.Entry) super.get(key);

[Demonstration 2]

[Buggy Method]
@RequestMapping(value = "/seckill", produces = "application/json; charset=utf-8")
@ResponseBody
public String test() {
    return "test";
}

[Buggy Hunk]
return "test";

[Patch]
return JSON.toJSONString(seckillService.seckillService(1001L));

[Demonstration 3]

[Buggy Method]
public static void testPdf() {
    double[] start = { 1, 2 };
    double[] stop = { 0, 0 };
    double[][] precision = { { 2, 0.5 }, { 0.5, 1 } };
    double scale = 0.2;
    System.err.println("logPDF = " + logPdf(start, stop, precision, Math.log(calculatePrecisionMatrixDeterminate(precision)), scale));
    System.err.println("Should = -19.94863\n");
    System.err.println("logPDF = " + logPdf(start, stop, 2, 0.2));
    System.err.println("Should = -24.53529\n");
}

[Buggy Hunk]
System.err.println("logPDF = " + logPdf(start, stop, precision, Math.log(calculatePrecisionMatrixDeterminate(precision)), scale));

[Patch]
System.err.println("logPDF = " + logPdf(start, stop, precision, Math.log(calculatePrecisionMatrixLogDeterminate(precision)), scale));