anchor.diff:  
             wrapProgram $out/bin/nixos-test-driver \
               --prefix PATH : "${lib.makeBinPath [ qemu_pkg vde2 netpbm coreutils ]}" \
  +
  +          install -m 0644 -vD driver-exports $out/nix-support/driver-exports
           '';
       };
   
  
positive.code: 
              echo -n "$testScript" > $out/test-script
              ${lib.optionalString (!skipLint) ''
                ${python3Packages.pyflakes}/bin/pyflakes $out/test-script
              ''}
  
              ln -s ${testDriver}/bin/nixos-test-driver $out/bin/
  
negative.code:       invalidNodeNames = lib.filter
          (node: builtins.match "^[A-z_]([A-z0-9_]+)?$" node == null)
          nodeNames;
  
        nodeHostNames = map (c: c.config.system.name) (lib.attrValues driver.nodes);
  
      in
      if lib.length invalidNodeNames > 0 then
  