anchor.diff:        // Currently we generate duplicates if a class is implemented by multiple
         // js-interop classes.
         typeTests.forEachProperty(_sorter, (js.Name name, js.Node code) {
  -        _classes[_commonElements.jsJavaScriptObjectClass]
  -            .isChecks
  -            .add(_buildStubMethod(name, code));
  +        _jsInteropIsChecks.add(_buildStubMethod(name, code));
         });
       } else {
         for (Field field in instanceFields) {
  
positive.code:     // a method in the case where there exist multiple JavaScript classes
      // that conflict on whether the member is a getter or a method.
      Class interceptorClass = _classes[_commonElements.jsJavaScriptObjectClass];
      Set<String> stubNames = {};
      librariesMap
          .forEach((LibraryEntity library, List<ClassEntity> classElements, _) {
  
negative.code: 
    Set<Class> _unneededNativeClasses;
  
    List<StubMethod> _jsInteropIsChecks = [];
  
    /// Classes that have been allocated during a profile run.
    ///
    /// These classes should not be soft-deferred.
  