code: public DebugSendResponseInner debugSend(String resourceGroupName, String namespaceName, String notificationHubName) {
          return debugSendWithServiceResponseAsync(resourceGroupName, namespaceName, notificationHubName).toBlocking().single().body();
      }
docs: test send a push notification.
  
  @param resourceGroupName The name of the resource group.
  @param namespaceName The namespace name.
  @param notificationHubName The notification hub name.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the DebugSendResponseInner object if successful.