code: public VMConsumptionComparator append(ShareableResource r, boolean asc) {
          rcs.add(r);
          ascs.add(asc ? 1 : -1);
          return this;
      }
docs: Append a new resource to use to make the comparison
  
  @param r   the resource to add
  @param asc {@code true} for an ascending comparison
  @return the current comparator