private ArrayList<String> getAggFieldNames(LogicalAggregate aggregate) {
    return aggregate.getAggCallList().stream().collect(ArrayList::new, (names, aggCall) -> names.add(aggCall.getName()),
      (n1, n2) -> n1.addAll(n2));
  }
Translator to translate the LogicalAggregate node in the relational graph to the corresponding StreamGraph
implementation
samza-sql/src/main/java/org/apache/samza/sql/translator/LogicalAggregateTranslator.java