'Returns serialized information about the manual enrollment
belonging to this enrollment, if it exists.
Args:
enrollment_data (dict): Representation of a single course enrollment.
course_key (CourseKey): The course for this enrollment.
Returns:
None: If no manual enrollment change has been made.
dict: Serialization of the latest manual enrollment change.'

@staticmethod
def manual_enrollment_data(enrollment_data, course_key):

    user = User.objects.get(username=enrollment_data['user'])
    enrollment = CourseEnrollment.get_enrollment(user, course_key)
    manual_enrollment_audit = ManualEnrollmentAudit.get_manual_enrollment(enrollment)
    if (manual_enrollment_audit is None):
        return {}
    return ManualEnrollmentSerializer(instance=manual_enrollment_audit).data
