Referencing a type/object in my mockserver?

[SubZane]

I've been looking through the documentation many times now and it doesn't seem to say anywhere how to reference another type object, just type lists of objects

so this is my scheme:

	type ProductTeam {
		id: Int!
		product_name: String
		product_description: String
		owner: User
	}

	type User {
		id: Int!
		first_name: String
		last_name: String
		email: String
		username: String
	}

and this is my mockdata:

	ProductTeam: () => ({
		id: casual.integer(0, 200),
		product_name: casual.title,
		product_description: casual._short_description,
                owner: User // <- how do I reference the user object?
 	}),

    // My user object that I want to reference above
	User: () => ({
		id: casual.integer(0, 200),
		first_name: casual.first_name,
		last_name: casual.last_name,
		email: casual.email,
		username: casual.username,
	}),

So how do I reference the user object in my mock?

I've tried
() => User
() => User()
User()

but seems to be all wrong :(