anchor.diff:  
   # to register web-server's ip address in DNS
   resource "google_dns_record_set" "default" {
  +  provider     = google-beta
     name         = google_dns_managed_zone.default.dns_name
     managed_zone = google_dns_managed_zone.default.name
     type         = "A"
  
positive.code: 
  # to allow http traffic
  resource "google_compute_firewall" "default" {
    name    = "<%= ctx[:vars]['allow_http_traffic'] %>"
    network = "default"
    allow {
      ports    = ["80"]
      protocol = "tcp"
  
negative.code: 
  # to create a DNS zone
  resource "google_dns_managed_zone" "<%= ctx[:primary_resource_id] %>" {
    provider      = google-beta
    name          = "<%= ctx[:vars]['example_zone_googlecloudexample'] %>"
    dns_name      = "googlecloudexample.com."
    description   = "Example DNS zone"
  