'Returns true if the edX Notes feature is enabled in the course.
Args:
course (CourseDescriptor): the course using the feature
settings (dict): a dict of configuration settings
user (User): the user interacting with the course'

@classmethod
def is_enabled(cls, course, user=None):

    if (not super(EdxNotesTab, cls).is_enabled(course, user=user)):
        return False
    if ((not settings.FEATURES.get('ENABLE_EDXNOTES')) or is_harvard_notes_enabled(course)):
        return False
    return course.edxnotes
