code: protected void generateRowStart(ResponseWriter writer, int row, String[] rowClasses, PanelGrid panelGrid) throws IOException {
  		writer.startElement("div", panelGrid);
  		if (null == rowClasses)
  			writer.writeAttribute("class", "row", "class");
  		else
  			writer.writeAttribute("class", "row " + rowClasses[row % rowClasses.length], "class");
  	}
docs: Generates the start of each Bootstrap row.
  
  @param writer
  the current response writer.
  @param row
  the current row index
  @param rowClasses
  the array of row classes
  @throws IOException
  if something's wrong with the response writer.