       default:
         XCTFail()
       }
+      self.stopMeasuring()
     }
   }
 
   func testPerformanceABAProneReduce()
   {
-    let iterations = loopTestCount
-
-    measure {
+    let iterations = 10 // loopTestCount
+
+    measureMetrics([XCTPerformanceMetric_WallClockTime], automaticallyStartMeasuring: false) {
       let inputs = (1...iterations).map {Deferred(value: $0) }
+      self.startMeasuring()
       let accumulator = Deferred(value: 0)
       let c = inputs.reduce(accumulator) {
         (accumulator, deferred) in

      default:
        XCTFail()
      }
    }
  }
}

  {
    let iterations = loopTestCount

    measureMetrics([XCTPerformanceMetric_WallClockTime], automaticallyStartMeasuring: false) {
      let inputs = (1...iterations).map { Deferred(value: $0) }
      self.startMeasuring()
      let c = combine(inputs)
      switch c.result
      {
