code: @Override
      public Geldbetrag divide(Number divisor) {
          BigDecimal d = toBigDecimal(divisor, context);
          if (BigDecimal.ONE.compareTo(d) == 0) {
              return this;
          }
          return Geldbetrag
                  .valueOf(betrag.setScale(4, RoundingMode.HALF_UP).divide(d, RoundingMode.HALF_UP), currency);
      }
docs: Returns a {@code MonetaryAmount} whose value is <code>this /
  divisor</code>, and whose preferred scale is <code>this.scale() -
  divisor.scale()</code>; if the exact quotient cannot be represented an {@code ArithmeticException}
  is thrown.
  
  @param divisor value by which this {@code MonetaryAmount} is to be divided.
  @return {@code this / divisor}
  @throws ArithmeticException if the exact quotient does not have a terminating decimal expansion, or if the
  result exceeds the numeric capabilities of this implementation class, i.e. the
  {@link MonetaryContext} cannot be adapted as required.