Throttle , similar to RxSwift's throttle but can be used on any arbitrary block

Throttle.swift

/// throttle a procedure for the given time interval, operation identifer is used to uniquely identify operation to prevent from firing multiple times
private var throttledOperations: Set<String> = []
func dispatchThrottle(_ interval: TimeInterval, operationIdentifier: String, queue: DispatchQueue = .main, _ closure: @escaping () -> Void) {
    guard !throttledOperations.contains(operationIdentifier) else { return }
    throttledOperations.insert(operationIdentifier)
    closure()
    queue.asyncAfter(deadline: .now() + interval) {
        throttledOperations.remove(operationIdentifier)
    }
}

//usage:

dispatchThrottle(2, operationIdentifier: "MyUniqueBlock") { 
    debugPrint("this block will execute only once within the given 2 second window") 
}