code: public void addFormatter(Formatter formatter) {
          if(_formatters == null)
              _formatters = new ArrayList/*<Formatter>*/();
  
          _formatters.add(formatter);
      }
docs: Add a {@link Formatter} which can be used to format an Object for rendering.  Many
  {@link Formatter} instances can be registered and will be executed in the order in
  which they were added.  This method is provided as a service to CellModel subclasses;
  the use of formatters can vary based on the implementation of a {@link CellDecorator}.
  
  @param formatter the {@link Formatter} to add