Adding comments to generated SQL #643

Is there a way to construct SQL statement in the usual way, then add a an SQL comment with custom content, to the query before sending it to the database? Ideally this comment would be able to be added at any point in the construction process; for example, I could add a comment to a filter_ and it would show up above the where in SQL. It would also be acceptable to only be able to add the comment right before runBeamPostgres or runSelect*; Maybe a different version of these functions that would take a comment string.