public ResourceAmounts subtract(ResourceAmounts amounts) {
   return ResourceAmounts.of(
       getCpu() - amounts.getCpu(),
       getMemory() - amounts.getMemory(),
       getDiskIO() - amounts.getDiskIO(),
       getNetworkIO() - amounts.getNetworkIO());
 }
 public ResourceAmounts append(ResourceAmounts amounts) {
   return ResourceAmounts.of(
       getCpu() + amounts.getCpu(),
       getMemory() + amounts.getMemory(),
       getDiskIO() + amounts.getDiskIO(),
       getNetworkIO() + amounts.getNetworkIO());
 }
 public boolean containsValuesLessThan(ResourceAmounts amounts) {
   return getCpu() < amounts.getCpu()
       || getMemory() < amounts.getMemory()
       || getDiskIO() < amounts.getDiskIO()
       || getNetworkIO() < amounts.getNetworkIO();
 }