// single direct fetching, which means FS is not needed any more when conversion completed.
// rows forwarded will be received by ListSinkOperator, which is replacing FS
private ListSinkOperator completed(ParseContext pctx, FetchWork work) {
pctx.getSemanticInputs().addAll(inputs);
ListSinkOperator sink = new ListSinkOperator();
sink.setConf(new ListSinkDesc(work.getSerializationNullFormat()));
sink.setParentOperators(new ArrayList<Operator<? extends OperatorDesc>>());
Operator<? extends OperatorDesc> parent = fileSink.getParentOperators().get(0);
sink.getParentOperators().add(parent);
parent.replaceChild(fileSink, sink);
fileSink.setParentOperators(null);