code: public BigDecimal getAmountMinor() {
          int cdp = getCurrencyUnit().getDecimalPlaces();
          return amount.setScale(cdp, RoundingMode.DOWN).movePointRight(cdp);
      }
docs: Gets the amount in minor units as a {@code BigDecimal} with scale 0.
  <p>
  This returns the monetary amount in terms of the minor units of the currency,
  truncating the amount if necessary.
  For example, 'EUR 2.35' will return 235, and 'BHD -1.345' will return -1345.
  <p>
  This is returned as a {@code BigDecimal} rather than a {@code BigInteger}.
  This is to allow further calculations to be performed on the result.
  Should you need a {@code BigInteger}, simply call {@link BigDecimal#toBigInteger()}.
  
  @return the minor units part of the amount, never null