zzzeek/sqlalchemy — pull request #131 by gthb (2014-08-21 18:51:11+00:00)
Title: Add note on begin_nested requiring rollback/commit

Avoid confusion about rollback/commit "must be issued" after
``session.begin_nested()`` --- this might be taken to mean call must be
*added*, but that's only true if not using the return value as a context
manager.