I want to use HKStatisticsQuery to read the Active Energy Burned from HealthKit

I have requested the access from the HealthKit by below code

let calorieCount = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.activeEnergyBurned)!

and it working perfectly but not able to read the data using Query after reading the documentation I have found out HKStatisticsQuery is used for Query

    func CaloriesBurned() {

        let activeEnergy = HKQuantityType.quantityType(forIdentifier: .activeEnergyBurned)!

        let startDate = Calendar.current.date(byAdding: .day,value: -7, to: Date())

        let predicate = HKQuery.predicateForSamples(withStart: startDate, end: Date(), options: .strictStartDate)

        let query = HKStatisticsQuery(quantityType: activeEnergy, quantitySamplePredicate: predicate,completionHandler: <#T##(HKStatisticsQuery, HKStatistics?, Error?) -> Void#>))

    }

but I don't understand what should be written in completion handler in above code to read the active Energy Burned

I have read already documentation if anyone has sample code to read energy burned or sample code on how to use HKStatisticsQuery