Merge pull request #1198 from edx/ned/fix-calling-classmethods

No need to invoke classmethods through self.__class__

lms/lib/comment_client/models.py

@@ -91,7 +91,7 @@ class Model(object):
         pass
 
     def save(self):
-        self.__class__.before_save(self)
+        self.before_save(self)
         if self.id:   # if we have id already, treat this as an update
             url = self.url(action='put', params=self.attributes)
             response = perform_request('put', url, self.updatable_attributes())
@@ -100,7 +100,7 @@ class Model(object):
             response = perform_request('post', url, self.initializable_attributes())
         self.retrieved = True
         self.update_attributes(**response)
-        self.__class__.after_save(self)
+        self.after_save(self)
 
     def delete(self):
         url = self.url(action='delete', params=self.attributes)