/** * Get only the {@link StreamRecord StreamRecords} emitted by the operator. */ @SuppressWarnings("unchecked") public List<StreamRecord<? extends OUT>> extractOutputStreamRecords() { List<StreamRecord<? extends OUT>> resultElements = new LinkedList<>(); for (Object e: getOutput()) { if (e instanceof StreamRecord) { resultElements.add((StreamRecord<OUT>) e); } } return resultElements; }