iOS - Sending Campaign Parameters

NSMutableDictionary *properties = [[NSMutableDictionary alloc] init];
[properties setObject:@"euromsg" forKey:@"utm_source"];
[properties setObject:@"push" forKey:@"utm_medium"];
[properties setObject:@"protein campaign" forKey:@"utm_campaign"];
[[Visilabs callAPI] customEvent:@"Login Page" withProperties:properties];

var properties = [String:String]()
properties["utm_source"] = "euromsg"
properties["utm_medium"] = "push"
properties["utm_campaign] = "protein campaign"
Visilabs.callAPI().customEvent("Login Page", withProperties: NSMutableDictionary(dictionary: properties))