private static async Task Delete(this ServiceBusAdministrationClient admin, string topic, string subscription, string rule)
 {
     if ((await admin.RuleExistsAsync(topic, subscription, rule)).Value)
     {
         await admin.DeleteRuleAsync(topic, subscription, rule);
     }
 }
 private static async Task SetupRule(this ServiceBusAdministrationClient admin, string topic, string subscription, string @event)
 {
     if (!(await admin.RuleExistsAsync(topic, subscription, @event)).Value)
     {
         await admin.CreateRuleAsync(topic, subscription,
                                     new CreateRuleOptions(@event, new CorrelationRuleFilter {
             Subject = @event
         }));
     }
 }