I have issue to request Authorization and get the total sleep hours from HealthKit func requestAuthorization(completion: @escaping (Bool) -> Void) {           let stepType = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)!     let heartRate = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate)!     let spo2 = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.respiratoryRate)!     let sleepHours = HKObjectType.categoryType(forIdentifier: .sleepAnalysis)     let setType = Set(arrayLiteral: sleep_type_t) //error cannot find 'sleepType' in scope ****           guard let healthStore = self.healthStore else { return completion(false) }           healthStore.requestAuthorization(toShare: [], read: [stepType,heartRate,spo2,sleepHours]) { (success, error) in       completion(success)     }         }    func getSleepHours(completion: @escaping (_ sleepHours: String?) -> Void) {     let sampleType = HKObjectType.categoryType(forIdentifier: HKCategoryTypeIdentifier.sleepAnalysis)!           // Get all samples from the last 24 hours     let endDate = Date()     let startDate = endDate.addingTimeInterval(-1.0 * 60.0 * 60.0 * 24.0)     let predicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: [])     let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: false)     // Sleep query     let sleepQuery = HKSampleQuery(sampleType: sampleType,predicate: predicate,limit: 0,sortDescriptors: [sortDescriptor]) { (query, results, error) -> Void in             if error != nil {return}             // Sum the sleep time             var minutesSleepAggr = 0.0             if let result = results {               for item in result {                 if let sample = item as? HKCategorySample {                   if sample.value == HKCategoryValueSleepAnalysis.asleep.rawValue && sample.startDate >= startDate {                       let sleepTime = sample.endDate.timeIntervalSince(sample.startDate)                       let minutesInAnHour = 60.0                       let minutesBetweenDates = sleepTime / minutesInAnHour                       minutesSleepAggr += minutesBetweenDates                   }                 }               }               let sleepHours = Double(String(format: "%.1f", minutesSleepAggr / 60))!               let sleepHours2 = "(sleepHours)"               completion(sleepHours2)               print("*** SLEEP HOURS: (String(describing: sleepHours))")             }       }               healthStore?.execute(sleepQuery)   }