How to group some fields under a new field

[mrasoahaingo]

From this

type User {
  firstName
  lastName
  street
  code
}

With this data

{
  "firstName": "John",
  "lastName": "Doe",
  "street": "1 street"
  "code": "11111"
}

To this

type User {
  firstName
  lastName
  address {
    street
    code
  }
}