presto-main/src/main/java/io/prestosql/sql/rewrite/ShowQueriesRewrite.java/ShowQueriesRewrite/visitExplain
class ShowQueriesRewrite:        @Override
        protected Node visitExplain(Explain node, Void context)
        {
            Statement statement = (Statement) process(node.getStatement(), null);
            return new Explain(
                    node.getLocation().get(),
                    node.isAnalyze(),
                    node.isVerbose(),
                    statement,
                    node.getOptions());
        }