title: Check if Azure Service Bus name is unique
body: <p>I am creating an Azure Service Bus with the Fluent SDK. I want to give my service bus a specific name and increment by one if the name is unavailable. 
  The problem I am having is that I don't actually know if the name is unavailable at the time of creation.</p>
  
  <p>I'm using this to create a service bus:</p>
  
  <pre><code>var serviceBusNamespace = azure.ServiceBusNamespaces
                              .Define(serviceBusName)
                              .WithRegion(Region)
                              .WithExistingResourceGroup(resourceGroup)
                              .WithSku(NamespaceSku.Standard)
                              .Create();
  </code></pre>
  
  <p>If I run this code for two different resource groups using the same <code>serviceBusName</code>, I get a service bus created in both resources groups without error. However when I go to the Azure portal the first service bus opens fine, but I get an error saying 'Not Found' when trying to open the second.</p>
  
  <p>I understand that servicebus names must be unique across all of Azure, but</p>
  
  <ol>
  <li>Why is the Fluent SDK allowing me to create the second service bus with the same name?</li>
  <li>How can I check of the name is unique before creating the service bus?</li>
  </ol>
  
  <p>I tried to ping the service bus URL to see if it exists. For example I tried <a href="https://stackoverflow.com/questions/7523741/how-do-you-check-if-a-website-is-online-in-c">this</a>, for a URL like <code>serviceBusName.servicebus.windows.net</code>, but that failed.</p>