 
   internal var _in: Storage
   internal var _out: Storage
-  
+
   public init() {
     _in = Storage()
     _out = Storage()
   }
 }
 
-extension Queue {  
+extension Queue {
   public mutating func enqueue(_ newElement: Element) {
     _in.append(newElement)
   }

  runFunction: run_QueueGeneric,
  tags: [.validation, .api],
  setUpFunction: { buildWorkload() },
  tearDownFunction: nil)

public let QueueConcrete = BenchmarkInfo(
  name: "QueueConcrete",
  runFunction: run_QueueConcrete,
  tags: [.validation, .api],
  setUpFunction: { buildWorkload() },
  tearDownFunction: nil)
 
// TODO: remove when there is a native equivalent in the std lib
extension RangeReplaceableCollection where Self: BidirectionalCollection {
  public mutating func popLast() -> Element? {

public struct ConcreteQueue {
  internal var _in: [String]
  internal var _out: [String]

  public init() {
    _in = Array()
    _out = Array()
  }
}

extension ConcreteQueue {
  public mutating func enqueue(_ newElement: String) {
    _in.append(newElement)
  }
