object {
  attr "name" {
    type     = string
    required = true
  }
  default "greeting" {
    attr {
      name = "greeting"
      type = string
    }
    literal {
      value = "Hello"
    }
  }
  block_list "friends" {
    block_type = "friend"
    attr {
      name     = "name"
      type     = string
      required = true
    }
  }
}