type Review @key(fields: "id") {
    id: ID!
    body: String
    author: User @provides(fields: "email")
    product: Product @provides(fields: "upc")
}

type User @key(fields: "email") @extends {
    email: String! @external
    reviews: [Review]
}

type Product @key(fields: "upc") @extends {
    upc: String! @external
    reviews: [Review]
}

type ReviewResponse implements Response{
    "Review Response"
    success: Boolean!
    errorMessage: String
    review: Review
}