anchor.diff:      List<LibraryElement> importedLibraries = library.importedLibraries;
       assertNamedElements(importedLibraries, ["dart.core", "libB"]);
       List<LibraryElement> visibleLibraries = library.visibleLibraries;
  -    assertNamedElements(visibleLibraries, ["dart.core", "libA", "libB"]);
  +    assertNamedElements(visibleLibraries, [
  +      "dart.core",
  +      "dart.async",
  +      "dart.math",
  +      "libA",
  +      "libB"
  +    ]);
     }
   
     void fail_resolveHtmlUnit() {
  
positive.code:     List<LibraryElement> importedLibraries = library.importedLibraries;
      assertNamedElements(importedLibraries, ["dart.core", "libB"]);
      List<LibraryElement> visibleLibraries = library.visibleLibraries;
      assertNamedElements(visibleLibraries, ["dart.core", "libA", "libB"]);
    }
  
    void fail_resolveCompilationUnit_import_relative_cyclic() {
      Source sourceA =
          addSource("/libA.dart", "library libA; import 'libB.dart'; class A{}");
      addSource("/libB.dart", "library libB; import 'libA.dart'; class B{}");
  
negative.code:     fail("Implement this");
    }
  
    void test_resolveCompilationUnit_import_relative() {
      Source sourceA =
          addSource("/libA.dart", "library libA; import 'libB.dart'; class A{}");
      addSource("/libB.dart", "library libB; class B{}");
  