docs: @Override
    public PackingPlan pack() {
      PackingPlanBuilder planBuilder = newPackingPlanBuilder(null);
  
      // Get the instances using FFD allocation
      try {
        planBuilder = getFFDAllocation(planBuilder);
      } catch (ConstraintViolationException e) {
        throw new PackingException("Could not allocate all instances to packing plan", e);
      }
  
      return planBuilder.build();
    }