Fixed 'course_was_registered' in Course slice.

Author: johnbywater

examples/coursebookingdcbslices/application.py

@@ -479,7 +479,7 @@ def cb(self) -> list[Selector]:
 
     @event(CourseRegistered)
     def _(self, name: str, places: int) -> None:
-        self.student_was_registered = True
+        self.course_was_registered = True
         self.name = name
         self.places = places