DispatchGroup not working with URLSession.shared.dataTask - ios

Question

I'm trying to implement many concurrent api calls through URLSession.shared singleton. What I want is that they are made concurrently so when I had all the responses, then execute the completion handler (I took this as example: https://medium.com/#oleary.audio/simultaneous-asynchronous-calls-in-swift-9c1f5fd3ea32):
init(completion: (()->Void)? = nil) throws {
self.myToken = myToken
let group = DispatchGroup()
group.enter()
print("Downloading User")
self.downloadUser(completion: { userObject in
self.userObject = userObject
group.leave()
})
group.enter()
print("Downloading Tickets")
self.downloadTickets(completion: { ticketsObject in
if let ticketsObject = ticketsObject {
self.ticketsObject = ticketsObject
}
group.leave()
})
group.wait()
completion?()
}
Then the functions the implement the api calls are something like:
private func downloadUser( completion: #escaping ((myUsuario)->Void )) {
let url = URL(string: "\(Globals.laravelAPI)me")
var request = URLRequest(url: url!)
let task = URLSession.shared.dataTask(with: request) {
(data:Data?, response:URLResponse?, error:Error?) in
if let error = error {
...
}
guard let httpResponse = response as? HTTPURLResponse,(200...299).contains(httpResponse.statusCode) else { ... }
if let data = data {
do {
let user = try JSONDecoder().decode(myUsuario.self, from: data)
completion(user)
} catch {
print("USER PARSING ERROR: \(error)")
fatalError()
}
}
}
task.resume()
}
When I run the program, it make the calls but never get the responses so the group.wait() is never executed.