@SuppressWarnings("unchecked")
        private <T> DataStreamSink<T> appendDummySink(SingleOutputStreamOperator<Void> committerStream) {
            DataStreamSink<T> resultStream = committerStream
                    .addSink(new DiscardingSink())
                    .name(operatorName(
                            String.format("IcebergSink %s", multipleSink ? "whole migration" : this.table.name())))
                    .setParallelism(1);
            if (uidPrefix != null) {
                resultStream = resultStream.uid(uidPrefix + "-dummysink");
            }
            return resultStream;
        }
Append the iceberg sink operators to write records to iceberg table.

@return {@link DataStreamSink} for sink.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/iceberg/src/main/java/org/apache/inlong/sort/iceberg/sink/FlinkSink.java