code: public static Comparator<MonetaryAmount> sortNumberDesc(){
  	        return new Comparator<MonetaryAmount>() {
  	            @Override
  	            public int compare(MonetaryAmount o1, MonetaryAmount o2) {
  	                return sortNumber().compare(o1, o2) * -1;
  	            }
  	        };
  	    }
docs: Get a comparator for sorting amount by number value descending.
  @return the Comparator to sort by number in descending way, not null.