I have an app that is developed with old swift code. now I'm updating it to latest swift syntax. While updating I found difficult in dispatch queue, here it's giving two warnings as global(priority) was deprecated in ios 8 and background was deprecated in ios 8.
DispatchQueue.global(priority: DispatchQueue.GlobalQueuePriority.background).async(execute: { [weak self] in     //Getting warning in this line
    if let strongSelf = self {
        strongSelf.populateOutBoundContacts()
        strongSelf.lookForContactsToPresent()
    }
})
 
     
    