throttle implementation class in swift

Throttler.swift

final class Throttler {

    private var throttleWorkItems: [AnyHashable: DispatchWorkItem] = [:]
    private var lastDebounceCallTimes: [AnyHashable: DispatchTime] = [:]
    private let nilContext: AnyHashable = arc4random()

    /// Delays a closure execution and ensures no other executions are made during deadline
    ///
    /// - Parameters:
    ///   - deadline: The timespan to delay a closure execution
    ///   - context: The context in which the throttle should be executed
    ///   - action: The closure to be executed
    func throttle(deadline: DispatchTime,
                  context: AnyHashable? = nil,
                  action: @escaping () -> Void) {

        let worker = DispatchWorkItem { [weak self] in

            guard let myself = self else { return }

            defer {
                myself.throttleWorkItems.removeValue(forKey: context ?? myself.nilContext)
            }
            action()
        }

        DispatchQueue.global(qos: .background).asyncAfter(deadline: deadline,
                                                          execute: worker)

        throttleWorkItems[context ?? nilContext]?.cancel()
        throttleWorkItems[context ?? nilContext] = worker
    }
}