       default:
         XCTFail()
       }
+      self.stopMeasuring()
     }
   }
 }

  {
    let iterations = loopTestCount

    measure {
      let inputs = (1...iterations).map { Deferred(value: $0) }
      let c = combine(inputs)
      switch c.result
      {

  {
    let iterations = loopTestCount

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