func loginWithOauth2(providerName: String, token: String, fieldsMapping: [String : String], stayLoggedIn: Bool, responseHandler: ((BackendlessUser) -> Void)!, errorHandler: ((Fault) -> Void)!)
func loginWithOauth2(providerName: String, token: String, guestUser: BackendlessUser, fieldsMapping: [String : String], stayLoggedIn: Bool, responseHandler: ((BackendlessUser) -> Void)!, errorHandler: ((Fault) -> Void)!)
func loginWithOauth1(providerName: String, token: String, tokenSecret: String, fieldsMapping: [String : String], stayLoggedIn: Bool, responseHandler: ((BackendlessUser) -> Void)!, errorHandler: ((Fault) -> Void)!)
func loginWithOauth1(providerName: String, token: String, tokenSecret: String, guestUser: BackendlessUser, fieldsMapping: [String : String], stayLoggedIn: Bool, responseHandler: ((BackendlessUser) -> Void)!, errorHandler: ((Fault) -> Void)!)
