def METHOD_NAME(apps, schema_editor):
    """
    Rollback functionality for:
    SIG-1831 [BE] de subcategorie “Put/ riolering verstopt” aan STW (Stadswerken)
    De subcategorie “Put/ riolering verstopt” moet toegewezen worden aan STW (Stadswerken)
    ipv WAT (Waternet).
    :param apps:
    :param schema_editor:
    :return:
    """
    Category = apps.get_model('signals', 'Category')
    Department = apps.get_model('signals', 'Department')
    department = Department.objects.get(code='WAT')
    sub_category = Category.objects.get(slug='put-riolering-verstopt', parent__isnull=False)
    sub_category.departments.clear()
    sub_category.departments.add(department)