type OrderingQuery {
  productCategories(manufacturer: String!): [OrderingProductCategory!]!
}

type OrderingProductCategory {
  name: String!
}

query {
  ordering {
    productCategories(manufacturer: "ge") {
      name
    }
  }
}

{
  "data": {
    "ordering": {
      "productCategories": [
        { "name": "Refrigerators" },
        { "name": "Dishwashers" },
        { "name": "Ranges" },
        { "name": "Washers" }
      ]
    }
  }
}