type Something
  @model
  @auth(rules: [{ allow: private, provider: iam }])
  @key(name: "byTodo", fields: ["todoID"])
  @key(name: "byTodo2", fields: ["todo2ID"])
  @key(name: "byTodo3", fields: ["todo3ID"]) {
  id: ID!
  todoID: ID!
  todo2ID: ID!
  todo3ID: ID!
}

type Todo @model {
  id: ID!
  name: String!
  description: String
  addfield2: String
  reltn: [Something] @connection(keyName: "byTodo", fields: ["id"])
}

type Todo2 @model {
  id: ID!
  name: String!
  description: String
  addfield2: String
  reltn: [Something] @connection(keyName: "byTodo2", fields: ["id"])
}

type Todo3 @model {
  id: ID!
  name: String!
  description: String
  addfield2: String
  reltn: [Something] @connection(keyName: "byTodo3", fields: ["id"])
}