anchor.diff:  
       users = {
         allowSignUp = mkOption {
  -        description = "Disable user signup / registration";
  +        description = "Disable user signup / registration.";
           default = false;
           type = types.bool;
         };
  
positive.code:       name = mkOption {
          type = types.str;
          default = "default";
          description = "Notifier name";
        };
        type = mkOption {
          type = types.enum ["dingding" "discord" "email" "googlechat" "hipchat" "kafka" "line" "teams" "opsgenie" "pagerduty" "prometheus-alertmanager" "pushover" "sensu" "sensugo" "slack" "telegram" "threema" "victorops" "webhook"];
          description = "Notifier type";
        };
        uid = mkOption {
          type = types.str;
          description = "Unique notifier identifier";
        };
        org_id = mkOption {
          type = types.int;
          default = 1;
          description = "Organization ID";
        };
        org_name = mkOption {
          type = types.str;
          default = "Main Org.";
          description = "Organization name";
        };
        is_default = mkOption {
          type = types.bool;
          description = "Is the default notifier";
          default = false;
        };
        send_reminder = mkOption {
          type = types.bool;
          default = true;
          description = "Should the notifier be sent reminder notifications while alerts continue to fire";
        };
        frequency = mkOption {
          type = types.str;
          default = "5m";
          description = "How frequently should the notifier be sent reminders";
        };
        disable_resolve_message = mkOption {
          type = types.bool;
          default = false;
          description = "Turn off the message that sends when an alert returns to OK";
        };
        settings = mkOption {
          type = types.nullOr types.attrs;
          default = null;
          description = "Settings for the notifier type";
        };
        secure_settings = mkOption {
          type = types.nullOr types.attrs;
          default = null;
          description = "Secure settings for the notifier type";
        };
      };
    };
  
negative.code:     smtp = {
        enable = mkEnableOption "smtp";
        host = mkOption {
          description = "Host to connect to.";
          default = "localhost:25";
          type = types.str;
        };
        user = mkOption {
          description = "User used for authentication.";
          default = "";
          type = types.str;
        };
  