presto-main/src/main/java/io/prestosql/sql/rewrite/ShowStatsRewrite.java/ShowStatsRewrite/Visitor
class ShowStatsRewrite:        public Visitor(Metadata metadata, Session session, List<Expression> parameters, Optional<QueryExplainer> queryExplainer, WarningCollector warningCollector)
        {
            this.metadata = requireNonNull(metadata, "metadata is null");
            this.session = requireNonNull(session, "session is null");
            this.parameters = requireNonNull(parameters, "parameters is null");
            this.queryExplainer = requireNonNull(queryExplainer, "queryExplainer is null");
            this.warningCollector = requireNonNull(warningCollector, "warningCollector is null");
        }