anchor.diff:  class SpreadsheetApp {
     external static UI getUi();
     external static Spreadsheet getActiveSpreadsheet();
  +  external static Sheet getActiveSheet();
  +  external static Range getActiveRange();
   }
   
   @JS()
  
positive.code: library hello;
  
  import 'package:js/js.dart';
  
  @JS()
  class DocumentApp {
  
negative.code:   external Sheet insertSheet([int index]);
    external void deleteSheet(Sheet sheet);
    external void deleteActiveSheet();
    external List<Sheet> getSheets();
  }
  
  @JS()
  class Sheet {
    external Range getActiveCell();
    external Range getRange(dynamic /*String or int*/ rowOrA1Notation, [int column, int rumRows, int numColumns]);
    external Range getDataRange();
    external int getMaxRows();
    external int getMaxColumns();
    external int getLastColumn();
    external int getLastRow();
    external String getName();
    external Sheet setName(String name);
    external Sheet clear();
    external Sheet clearContents();
    external Sheet clearFormats();
    external Sheet setColumnWidth(int columnIndex, int width);
    external Sheet insertRowAfter(int afterPosition);
    external Sheet insertRowBefore(int beforePosition);
    /// [numRows] is defaulting to 1.
    external void insertRows(rowIndex, [int numRows]);
    external Sheet insertRowsAfter(int afterPosition, int howMany);
    external Sheet insertRowsBefore(int beforePosition, int howMany);
  }
  
  @JS()
  