docs: public BigDecimal getBigDecimal(int columnIndex) {
  		Object fieldValue = data[columnIndex];
  		if (fieldValue == null) {
  			return null;
  		}
  		if (fieldValue instanceof BigDecimal) {
  			return (BigDecimal) fieldValue;
  		}
  		throw new DBFException("Unsupported type for BigDecimal at column:" + columnIndex + " "
  				+ fieldValue.getClass().getCanonicalName());
  	}