code: func (a admissionRequirementList) subtract(pods ...*v1.Pod) admissionRequirementList {
  	newList := []*admissionRequirement{}
  	for _, req := range a {
  		newQuantity := req.quantity
  		for _, pod := range pods {
  			newQuantity -= resource.GetResourceRequest(pod, req.resourceName)
  		}
  		if newQuantity > 0 {
  			newList = append(newList, &admissionRequirement{
  				resourceName: req.resourceName,
  				quantity:     newQuantity,
  			})
  		}
  	}
  	return newList
  }
docs: // subtract returns a new admissionRequirementList containing remaining requirements if the provided pod
  // were to be preempted