def enrolled_courses(self, enterprise_customer_user):
courses_string = mark_safe(self.get_enrolled_course_string(enterprise_customer_user))<EOL>return courses_string or '<STR_LIT:None>'<EOL>
Return a string representing the courses a given EnterpriseCustomerUser is enrolled in

Args:
    enterprise_customer_user: The instance of EnterpriseCustomerUser
        being rendered with this admin form.