Swift SDK - no code returned for 'HTTPError'

I am using the Swift SDK v2 and I want to be able to interpret errors returned when there is no internet connection. So for 

files.listFolder

the returned error only contains a description saying "HTTP Error:" without any code or anything else. When I try to switch on HTTPError as suggested here, I am getting the following:

"http error code: nil - message: Optional("") - requestID: nil"

for the following code:

 

                if let error = error {
                    switch error {
                    case let .HTTPError(code, message, requestID):
                        print("http error code: \(code) - message: \(message) - requestID: \(requestID) ")
                    default:
                        print("some other error")
                    }
                } else {
                    print("there was no error")
                }