anchor.diff:          String source = outerContext
               .generate(innerContext.generate(expression.generate("")));
           String compileResult = await compiler.compile(source);
  +        compilerAndOptions.options.skipPlatformVerification = true;
           if (compileResult != "") {
             if (!hasNewline) print("");
             hasNewline = true;
  
positive.code:     return sb.toString();
    }
  
    static Future<TestCompiler> initialize() async {
      final Uri base = Uri.parse("org-dartlang-test:///");
      final Uri sdkSummary = base.resolve("vm_platform_strong.dill");
      final Uri sdkRoot = computePlatformBinariesLocation(forceBuildDir: true);
      Uri platformUri = sdkRoot.resolve("vm_platform_strong.dill");
      final List<int> sdkSummaryData =
          await new File.fromUri(platformUri).readAsBytes();
      MemoryFileSystem fs = new MemoryFileSystem(base);
      fs.entityForUri(sdkSummary).writeAsBytesSync(sdkSummaryData);
  
  
negative.code:     return "// @dart = 2.9\n${beforePlug}${plug}${afterPlug}";
    }
  }
  
  class CompilerAndOptions {
    final TestCompiler compiler;
    final CompilerOptions options;
  
    CompilerAndOptions(this.compiler, this.options);
  }
  