anchor.diff:      inherit (cfg) contents format;
       pkgs = import ../../../.. { inherit (pkgs) system; }; # ensure we use the regular qemu-kvm package
       partitioned = config.ec2.hvm;
  -    diskSize = if config.ec2.hvm then 2048 else 8192;
  +    diskSize = sizeMB;
       configFile = pkgs.writeText "configuration.nix"
         ''
           {
  
positive.code:       '';
      };
  
      format = mkOption {
        type = types.enum [ "raw" "qcow2" "vpc" ];
        default = "qcow2";
  
negative.code:         }
        '';
    };
  }
  