'Find a verified mode for a particular course.
Since we have multiple modes that can go through the verify flow,
we want to be able to select the \'correct\' verified mode for a given course.
Currently, we prefer to return the professional mode over the verified one
if both exist for the given course.
Arguments:
course_id (CourseKey): Search for course modes for this course.
Keyword Arguments:
modes (list of `Mode`): If provided, search through this list
of course modes.  This can be used to avoid an additional
database query if you have already loaded the modes list.
Returns:
Mode or None'

@classmethod
def verified_mode_for_course(cls, course_id, modes=None):

    modes_dict = cls.modes_for_course_dict(course_id, modes=modes)
    verified_mode = modes_dict.get('verified', None)
    professional_mode = modes_dict.get('professional', None)
    return (professional_mode if professional_mode else verified_mode)
