presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitShowStatsForQuery
class AstBuilder:    @Override
    public Node visitShowStatsForQuery(SqlBaseParser.ShowStatsForQueryContext context)
    {
        QuerySpecification specification = (QuerySpecification) visitQuerySpecification(context.querySpecification());
        return new ShowStats(Optional.of(getLocation(context)), new TableSubquery(query(specification)));
    }