extend schema
    @link(
        url: "https://specs.apollo.dev/federation/v2.3",
        import: ["@key", "@external", "@requires"]
     )

type Query {
  course(id: ID!): Course
  courses: [Course]
}

type Course @key(fields: "id") {
  id: ID!
  name: String
  description: String
}

extend type Enrollment @key(fields: "studentId courseId") {
  studentId: ID! @external
  courseId: ID! @external
  enrollmentDetails: Enrollment @requires(fields: "studentId courseId")
}