This copies the log of emit_event in CourseEnrollment—there was a place where I needed to be able to emit an event, but didn't have a CourseEnrollment object lying around, so I thought it might make sense to have a universal helper method for event emission.  Gabe, you may know more about this than me—does that make sense? if so, should I go ahead and change stuff so this is the only emit_event that anyone uses?