code: func SubtractWithNonNegativeResult(a corev1.ResourceList, b corev1.ResourceList) corev1.ResourceList {
  	zero := resource.MustParse("0")
  
  	result := corev1.ResourceList{}
  	for key, value := range a {
  		quantity := *value.Copy()
  		if other, found := b[key]; found {
  			quantity.Sub(other)
  		}
  		if quantity.Cmp(zero) > 0 {
  			result[key] = quantity
  		} else {
  			result[key] = zero
  		}
  	}
  
  	for key := range b {
  		if _, found := result[key]; !found {
  			result[key] = zero
  		}
  	}
  	return result
  }
docs: // SubtractWithNonNegativeResult - subtracts and returns result of a - b but
  // makes sure we don't return negative values to prevent negative resource usage.