anchor.diff:              ipAddress = "192.168.1.11";
             }
           ];
  -        description = ''
  +        description = "
             A list mapping ethernet addresses to IP addresses for the
             DHCP server.
  -        '';
  +        ";
         };
   
       };
  
positive.code:     nix = mkOption {
        default = pkgs: pkgs.nix;
        example = pkgs: pkgs.nixCustomFun /root/nix.tar.gz;
        description = ''
          Use non-default Nix easily. Be careful, though, not to break everything.
        '';
      };
  
    };
  
negative.code:   nesting = {
      children = mkOption {
        default = [];
        description = "
          Additional configurations to build.
        ";
      };
    };
  
  