presto-spi/src/main/java/io/prestosql/spi/connector/GroupingProperty.java/GroupingProperty/GroupingProperty
class GroupingProperty:    @JsonCreator
    public GroupingProperty(@JsonProperty("columns") Collection<E> columns)
    {
        requireNonNull(columns, "columns is null");

        this.columns = unmodifiableSet(new LinkedHashSet<>(columns));
    }