code: private StringBuffer format(BigDecimal number, StringBuffer result,
                                  FieldPosition fieldPosition) {
          fieldPosition.setBeginIndex(0);
          fieldPosition.setEndIndex(0);
          return format(number, result, fieldPosition.getFieldDelegate());
      }
docs: Formats a BigDecimal to produce a string.
  @param number    The BigDecimal to format
  @param result    where the text is to be appended
  @param fieldPosition    On input: an alignment field, if desired.
  On output: the offsets of the alignment field.
  @return The formatted number string
  @exception        ArithmeticException if rounding is needed with rounding
  mode being set to RoundingMode.UNNECESSARY
  @see java.text.FieldPosition