anchor.diff:      String context = 'in $member:\n'
           'Expected: $expectedImpact\nActual: $typeUses';
       for (TypeUse typeUse in typeUses) {
  -      String type = '${typeUse.type}';
  +      String type = printType(typeUse.type);
         switch (typeUse.kind) {
           case TypeUseKind.AS_CAST:
             Expect.isTrue(asCasts.contains(type), "Extra $typeUse $context");
  
positive.code:     'method13': new Impact(implicitCasts: ['int'], parameterChecks: ['String']),
    };
  
    retainDataForTesting = true;
    CompilationResult result =
        await runCompiler(memorySourceFiles: {'main.dart': source});
    Expect.isTrue(result.isSuccess);
    Compiler compiler = result.compiler;
  
    KClosedWorld closedWorld = compiler.frontendClosedWorldForTesting;
    ElementEnvironment elementEnvironment = closedWorld.elementEnvironment;
  
negative.code: import 'package:compiler/src/compiler.dart';
  import 'package:compiler/src/common_elements.dart';
  import 'package:compiler/src/elements/entities.dart';
  import 'package:compiler/src/elements/types.dart';
  import 'package:compiler/src/world.dart';
  import 'package:compiler/src/universe/use.dart';
  import 'package:compiler/src/universe/world_impact.dart';
  