code: protected String fixedInput (
          String type, String name, Object value, String extra)
      {
          StringBuilder buf = new StringBuilder();
          buf.append("<input type=\"").append(type).append("\"");
          buf.append(" name=\"").append(name).append("\"");
          buf.append(" value=\"").append(value).append("\"");
          if (!StringUtil.isBlank(extra)) {
              buf.append(" ").append(extra);
          }
          buf.append(getCloseBrace());
          return buf.toString();
      }
docs: Generates an input form field with the specified type, name, value
  and extra attributes. The value is not fetched from the request
  parameters but is always the value supplied.