/// <summary>
 /// Creates a virtual wan vpn gateway if it doesn't exist else updates the
 /// existing gateway.
 /// </summary>
 /// <param name='operations'>
 /// The operations group for this extension method.
 /// </param>
 /// <param name='resourceGroupName'>
 /// The resource group name of the VpnGateway.
 /// </param>
 /// <param name='gatewayName'>
 /// The name of the gateway.
 /// </param>
 /// <param name='vpnGatewayParameters'>
 /// Parameters supplied to create or Update a virtual wan vpn gateway.
 /// </param>
 /// <param name='cancellationToken'>
 /// The cancellation token.
 /// </param>
 public static async Task <VpnGatewayInner> CreateOrUpdateAsync(this IVpnGatewaysOperations operations, string resourceGroupName, string gatewayName, VpnGatewayInner vpnGatewayParameters, CancellationToken cancellationToken = default(CancellationToken))
 {
     using (var _result = await operations.CreateOrUpdateWithHttpMessagesAsync(resourceGroupName, gatewayName, vpnGatewayParameters, null, cancellationToken).ConfigureAwait(false))
     {
         return(_result.Body);
     }
 }