presto-parser/src/main/java/io/prestosql/sql/tree/GroupBy.java/GroupBy/GroupBy
class GroupBy:    private GroupBy(Optional<NodeLocation> location, boolean isDistinct, List<GroupingElement> groupingElements)
    {
        super(location);
        this.isDistinct = isDistinct;
        this.groupingElements = ImmutableList.copyOf(requireNonNull(groupingElements));
    }