code: private String typesToString(final List<String> types) {
  		if (types == null || types.isEmpty()) {
  			return null;
  		}
  
  		StringBuffer typesString = new StringBuffer();
  
  		for (Iterator<String> iter = types.iterator(); iter.hasNext();) {
  			typesString.append(iter.next());
  
  			if (iter.hasNext()) {
  				typesString.append(',');
  			}
  		}
  
  		return typesString.toString();
  	}
docs: Flattens the list of accepted mime types into a format suitable for rendering.
  
  @param types the list of accepted mime types
  @return the list of accepted mime types in a format suitable for rendering