PreGroupingVariableExtractor extractor = new PreGroupingVariableExtractor(specs);
extractor.visit(_filteredReturnExpr, dynEnv);
List<BindingVariable> nonGroupingVariables = extractor.getNonGroupingVariables();
input = new GroupedSequence(input, specs, nonGroupingVariables, contextSeq, dynEnv, _groupByClause.isOrdering());
}
// where + return
Sequence ret = new PipedActionSequence(input, _filteredReturnExpr, dynEnv);
// order by TODO PERFORMANCE eager ordering
if(!_orderSpecs.isEmpty()) {