public static async Task <User> removeProxyId(string externalId, string proxyIdToUnregister) { User user = new User(); user.external_id = externalId; ProxyId proxyId = new ProxyId(); proxyId.unregister = proxyIdToUnregister; user.proxyId = proxyId; string route = APIRoutes.addRemoveProxyIdWithExternalIdRoute(externalId); SMResponse m = await AsyncClient.put(route, ConstructSMRequest(user)); return(m == null ? null : m.user); }