anchor.diff:  
   library fasta.test.expression_test;
   
  -import "dart:convert" show JsonEncoder;
  -
   import "dart:io" show File, IOSink;
   
   import 'dart:typed_data' show Uint8List;
  
positive.code:           className,
            methodName,
            expression);
        var result = test.validate();
        if (result != null) {
          return new Result.fail(tests, result);
        }
  
negative.code:       }
      }
      List<TypeParameter>? typeParams = createTypeParametersWithBounds(
          compilerResult.classHierarchy?.knownLibraries,
          test.typeBounds,
          test.typeDefaults,
          test.typeDefinitions);
  