code: public static String percentageGraph(int perc, int width) throws IOException {
      assert perc >= 0; assert perc <= 100;
  
      StringBuilder builder = new StringBuilder();
  
      builder.append("<table border=\"1px\" width=\""); builder.append(width);
      builder.append("px\"><tr>");
      if(perc > 0) {
        builder.append("<td cellspacing=\"0\" class=\"perc_filled\" width=\"");
        builder.append(perc); builder.append("%\"></td>");
      }if(perc < 100) {
        builder.append("<td cellspacing=\"0\" class=\"perc_nonfilled\" width=\"");
        builder.append(100 - perc); builder.append("%\"></td>");
      }
      builder.append("</tr></table>");
      return builder.toString();
    }
docs: Generate the percentage graph and returns HTML representation string
  of the same.
  
  @param perc The percentage value for which graph is to be generated
  @param width The width of the display table
  @return HTML String representation of the percentage graph
  @throws IOException