anchor.diff:    void _initializeEnclosingElements() {
       if (!_hasEnclosingElementsInitialized) {
         _EnclosingElementFinder finder = new _EnclosingElementFinder();
  -      finder.find(dartFileEditBuilder.unit, offset);
  +      finder.find(dartFileEditBuilder.resolvedUnit.unit, offset);
         _enclosingClass = finder.enclosingClass;
         _enclosingExecutable = finder.enclosingExecutable;
         _hasEnclosingElementsInitialized = true;
  
positive.code:     }
      int timeStamp = state == ResultState.VALID ? 0 : -1;
  
      CompilationUnit unit = result.unit;
      CompilationUnitElement declaredUnit = unit.declaredElement;
      CompilationUnitElement libraryUnit =
          declaredUnit.library.definingCompilationUnit;
  
  
negative.code:       });
      }
  
      return DartFileEditBuilderImpl(this, result, timeStamp, libraryEditBuilder);
    }
  }
  
  