DispatchWorkItem.swift

import Foundation

class Search {
    private var suggestedCitiesWorkItem: DispatchWorkItem?
    
    func getSuggestedCities(for prefix: String) {
        // here cancelling the previous workitem before assigning the new one
        suggestedCitiesWorkItem?.cancel()
        
        let workItem: DispatchWorkItem = DispatchWorkItem {
            NetworkManager.shared.getSuggestedCities(for: prefix) { response in
                // Instructions for response get from the API call
            }
        }
        
        suggestedCitiesWorkItem = workItem
        // executing the workitem after 1 second
        DispatchQueue.global().asyncAfter(deadline: .now() + .seconds(1), execute: workItem)
    }
}