anchor.diff:      expect(cwchst.getSubtypesOf(g), unorderedEquals([g, h]));
       expect(cwchst.getSubtypesOf(h), unorderedEquals([h]));
     }
  -}
  -
  -abstract class _ClassHierarchyTest {
  -  Component component;
  -  CoreTypes coreTypes;
  -
  -  /// The test library.
  -  Library library;
  -
  -  ClassHierarchy _hierarchy;
   
     /// Return the new or existing instance of [ClassHierarchy].
     ClassHierarchy get hierarchy {
  
positive.code:         implementedTypes: implements_.map((c) => c.asThisSupertype).toList()));
    }
  
    ClassHierarchy createClassHierarchy(Component component);
  
    Procedure newEmptyGetter(String name,
        {DartType returnType: const DynamicType(), bool isAbstract: false}) {
      var body =
  
negative.code: }
  
  @reflectiveTest
  class ClosedWorldClassHierarchyTest {
    Component component;
    CoreTypes coreTypes;
  
    /// The test library.
    Library library;
  
    ClassHierarchy _hierarchy;
  
    ClassHierarchy createClassHierarchy(Component component) {
      return new ClassHierarchy(component);
    }
  