code: public static void decrComputeSpecs(ComputeSpecs target, ComputeSpecs decr) {
      target.numCpus -= decr.numCpus;
      target.memoryMB -= decr.memoryMB;
      target.diskGB -= decr.diskGB;
    }
docs: Decrease the compute specs by decr
  @param target the specs to decrease
  @param decr the decrement