anchor.diff:        '';
       };
   
  -    hardware.nvidia.optimus_prime.intelBusId = lib.mkOption {
  -      type = lib.types.str;
  +    hardware.nvidia.optimus_prime.intelBusId = mkOption {
  +      type = types.str;
         default = "";
         example = "PCI:0:2:0";
         description = ''
  
positive.code:       '';
      };
  
      hardware.nvidia.optimus_prime.allowExternalGpu = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = ''
          Configure X to allow external NVIDIA GPUs when using optimus.
        '';
      };
  
      hardware.nvidia.optimus_prime.nvidiaBusId = lib.mkOption {
        type = lib.types.str;
        default = "";
        example = "PCI:1:0:0";
        description = ''
  
negative.code: 
      # nvidia-uvm is required by CUDA applications.
      boot.kernelModules = [ "nvidia-uvm" ] ++
        optionals config.services.xserver.enable [ "nvidia" "nvidia_modeset" "nvidia_drm" ];
  
      # If requested enable modesetting via kernel parameter.
      boot.kernelParams = optional cfg.modesetting.enable "nvidia-drm.modeset=1";
  