anchor.diff:          let fmt = VkFormat.ofPixFormat (PixFormat(typeof<'a>, format))
           let usage = VkImageUsageFlags.TransferSrcBit ||| VkImageUsageFlags.TransferDstBit ||| usage
   
  +        let mutable flushAfterUpload = true
  +
   
           let updateLock = new ReaderWriterLockSlim()
           let memory = device.DeviceMemory.Copy()
  
positive.code:         let totalSize = 
              sparseRequirements |> Array.sumBy (fun r ->
                  let singleMipTail = r.formatProperties.flags.HasFlag(VkSparseImageFormatFlags.SingleMiptailBit)
                  let mipTailSize = min r.imageMipTailSize (64UL <<< 20) |> int64
                  if singleMipTail then
                      mipTailSize
                  else
  
negative.code:         [<CLIEvent>]
          member x.OnSwap = onSwap.Publish
  
          member x.FlushAfterUpload 
              with get () = flushAfterUpload
              and set v = flushAfterUpload <- v
  
          member private x.Revoke(bind : SparseImageBind) =
              ReaderWriterLock.read updateLock (fun () ->
  