 
 final class QUnbufferedChan<T>: Chan<T>
 {
-  // housekeeping variables
+  // MARK: private housekeeping
 
   private let readerQueue = SemaphoreQueue()
   private let writerQueue = SemaphoreQueue()

  */

  final override var isClosed: Bool { return closed }

  /**
    Close the channel

  // Used to elucidate/troubleshoot message arrival order
  // private var readerCount: Int32 = -1

  // MARK: ChannelType properties

  final override var isEmpty: Bool
  {
