code: public void setCheckType(int checkType) {
          if (checkType < TYPE_CHECK || checkType > TYPE_STAR)
              checkType = TYPE_CHECK;
          this.checkType = checkType;
          setText(typeChars[checkType - 1]);
          try {
              setFont(BaseFont.createFont(BaseFont.ZAPFDINGBATS, BaseFont.WINANSI, false));
          }
          catch (Exception e) {
              throw new ExceptionConverter(e);
          }
      }
docs: Sets the checked symbol. It can be
  <CODE>TYPE_CHECK</CODE>,
  <CODE>TYPE_CIRCLE</CODE>,
  <CODE>TYPE_CROSS</CODE>,
  <CODE>TYPE_DIAMOND</CODE>,
  <CODE>TYPE_SQUARE</CODE> and
  <CODE>TYPE_STAR</CODE>.
  @param checkType the checked symbol