anchor.diff:  }
   
   class TextFormatter extends CellFormatter {
  +  TextFormatter([nextHandler]) : super(nextHandler);
  +
     bool _handleRequest(Event e) {
       var input = e.target;
       input.style.textAlign = 'left';
  
positive.code: abstract class CellFormatter {
    CellFormatter nextHandler;
  
    void processRequest(Event e) {
      if (!isCell(e)) return;
      if (_handleRequest(e)) return;
      if (nextHandler == null) return;
  
      nextHandler.processRequest(e);
    }
  
    // Subclasses handle requests as needed
  
negative.code: }
  
  class NumberFormatter extends CellFormatter {
    NumberFormatter([nextHandler]) : super(nextHandler);
  
    bool _handleRequest(Event e) {
      var input = e.target;
      RegExp exp = new RegExp(r"^\s*[\d\.]+\s*$");
  