[Demonstration 1]

[Buggy Method]
private Observable<Boolean> findPatient(String healthId) {
    Observable<ResultSet> observable = Observable.from(cqlOperations.queryAsynchronously(patientQueryBuilder.findPatientQuery(healthId)));
    return observable.flatMap(new Func1<ResultSet, Observable<Boolean>>() {

        @Override
        public Observable<Boolean> call(ResultSet rows) {
            return Observable.just(rows.one().getInt(0) > 0);
        }
    }, onError(), onCompletion());
}

[Buggy Hunk]
private Observable<Boolean> findPatient(String healthId) {

[Patch]
private Observable<Boolean> findPatient(final String healthId) {

[Demonstration 2]

[Buggy Method]
private Observable<?> oneOf(Observable<?> trigger, Observable<?> pending) {
    if (trigger == null) {
        return Observable.just(null);
    }
    return Observable.merge(trigger, pending);
}

[Buggy Hunk]
return Observable.just(null);

[Patch]
return Observable.just(new Object());

[Demonstration 3]

[Buggy Method]
public String createKey(String p, String ns, String local) {
    StringBuilder builder = new StringBuilder();
    String jns = getJSONNamespace(ns);
    if (jns != null && jns.length() != 0) {
        builder.append(jns).append('.');
    }
    return builder.append(local).toString();
}

[Buggy Hunk]
StringBuilder builder = new StringBuilder();

[Patch]
StringBuffer builder = new StringBuffer();