code: func (a AzureClient) CleanupVirtualNetworkIfExists(resourceGroup, name string) error {
  	return a.cleanupResourceIfExists(&vnetCleanup{rg: resourceGroup, name: name})
  }
docs: // CleanupVirtualNetworkIfExists removes a subnet if there are no subnets
  // attached to it. Note that this method is not safe for multiple concurrent
  // writers, in case of races, deployment of a machine could fail or resource
  // might not be cleaned up.