anchor.diff:    environment["updateExpectations"] =
         const String.fromEnvironment("updateExpectations");
     return ClosureConversionContext.create(suite, environment);
  -}
  -
  -class FastaCompile
  -    extends Step<TestDescription, Program, ClosureConversionContext> {
  -  const FastaCompile();
  -
  -  String get name => "fasta compilation";
  -
  -  Future<Result<Program>> run(
  -      TestDescription description, ClosureConversionContext context) async {
  -    Program platform = await context.loadPlatform();
  -    Ticker ticker = new Ticker();
  -    DillTarget dillTarget = new DillTarget(ticker, context.uriTranslator,
  -        new VmFastaTarget(new TargetFlags(strongMode: context.strongMode)));
  -    platform.unbindCanonicalNames();
  -    dillTarget.loader.appendLibraries(platform);
  -    KernelTarget sourceTarget = new KernelTarget(
  -        PhysicalFileSystem.instance, dillTarget, context.uriTranslator);
  -
  -    Program p;
  -    try {
  -      sourceTarget.read(description.uri);
  -      await dillTarget.buildOutlines();
  -      await sourceTarget.buildOutlines();
  -      p = await sourceTarget.buildProgram();
  -    } on deprecated_InputError catch (e, s) {
  -      return fail(null, e.error, s);
  -    }
  -    return pass(p);
  -  }
   }
   
   class ArgumentExtraction
  
positive.code: 
  import 'dart:async' show Future;
  
  import 'package:front_end/physical_file_system.dart' show PhysicalFileSystem;
  import 'package:front_end/src/fasta/uri_translator_impl.dart';
  
  import 'package:kernel/core_types.dart' show CoreTypes;
  
  import 'package:testing/testing.dart'
      show Chain, ChainContext, Result, Step, TestDescription, runMe;
  
  import 'package:front_end/src/fasta/testing/patched_sdk_location.dart'
      show computePatchedSdk;
  
  import 'package:kernel/ast.dart' show Program, Library;
  
  
negative.code:     as closure_conversion;
  
  import 'package:front_end/src/fasta/testing/kernel_chain.dart'
      show
          Compile,
          CompileContext,
          Print,
          MatchExpectation,
          WriteDill,
          ReadDill,
          Verify;
  
  const String STRONG_MODE = " strong mode ";
  
  class ClosureConversionContext extends ChainContext implements CompileContext {
    final bool strongMode;
  
    final List<Step> steps;
  
    ClosureConversionContext(this.strongMode, bool updateExpectations)
        : steps = <Step>[
            const Compile(),
            const Print(),
            const Verify(true),
            const ArgumentExtraction(),
  