type Book {
  id: Int!
  title: String!
  author: Author!
}

type Author {
  id: Int!
  name: String!
  books: [Book!]!
}

type Query {
  author(name: String! = ".*"): Author
  book(title: String! = ".*"): Book
  authors: [Author!]!
  books: [Book!]!
}

type Subscription {
  books: Book!
}

schema {
  query: Query
  subscription: Subscription
}