   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let kv = gen.next() {
-    pairs.append(kv)
+    pairs.append((kv.0.value, kv.1.value))
   }
   var expectedPairs = Array<(Int, Int)>()
   for i in 1...32 {

  var gen = d.generate()
  var pairs = Array<(Int, Int)>()
  while let kv = gen.next() {
    pairs.append(kv)
  }
  var expectedPairs = [ (10, 1111), (20, 1111), (30, 1111), (40, 1111) ]
  assert(equalsUnordered(pairs, expectedPairs))

    var gen = d.generate()
    var pairs = Array<(Int, Int)>()
    while let kv = gen.next() {
      pairs.append((kv.0.value, kv.1.value))
    }
    var expectedPairs = [ (10, 1010 + i), (20, 1020 + i), (30, 1030 + i) ]
    assert(equalsUnordered(pairs, expectedPairs))
