code: func memoryUsage(memStats *statsapi.MemoryStats) *resource.Quantity {
  	if memStats == nil || memStats.WorkingSetBytes == nil {
  		return &resource.Quantity{Format: resource.BinarySI}
  	}
  	usage := int64(*memStats.WorkingSetBytes)
  	return resource.NewQuantity(usage, resource.BinarySI)
  }
docs: // memoryUsage converts working set into a resource quantity.