anchor.diff:  
               echo -n "$testScript" > $out/test-script
               ${lib.optionalString (!skipLint) ''
  -              ${python3Packages.pyflakes}/bin/pyflakes $out/test-script
  +              PYFLAKES_BUILTINS="$(
  +                echo -n ${lib.escapeShellArg (lib.concatStringsSep "," nodeHostNames)},
  +                < ${lib.escapeShellArg "${testDriver}/nix-support/driver-exports"}
  +              )" ${python3Packages.pyflakes}/bin/pyflakes $out/test-script
               ''}
   
               ln -s ${testDriver}/bin/nixos-test-driver $out/bin/
  
positive.code: 
        preferLocalBuild = true;
  
        doCheck = true;
        checkPhase = ''
          mypy --disallow-untyped-defs \
  
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
  