anchor.diff:        print Test.a
       '';
   
  -    python3 = writePython3 "test_python3" { libraries = [ python3Packages.pyyaml ]; } ''
  +    python3 = writePython3 "test_writers_python3" { libraries = [ python3Packages.pyyaml ]; } ''
         import yaml
   
         y = yaml.load("""
  
positive.code:     '');
    };
  
    writeTest = expectedValue: test:
      writeDash "test-writers" ''
        if test "$(${test})" != "${expectedValue}"; then
          echo 'test ${test} failed'
          exit 1
  
negative.code:   passthru = { inherit writeTest bin simple; };
    meta.platforms = lib.platforms.all;
  } ''
    ${lib.concatMapStringsSep "\n" (test: writeTest "success" test.name "${test}/bin/${test.name}") (lib.attrValues bin)}
    ${lib.concatMapStringsSep "\n" (test: writeTest "success" test.name test) (lib.attrValues simple)}
    ${lib.concatMapStringsSep "\n" (test: writeTest "success" test.name test) (lib.attrValues path)}
  
    echo 'nix-writers successfully tested' >&2
    touch $out
  