/// <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>
 public static VpnGateway CreateOrUpdate(this IVpnGatewaysOperations operations, string resourceGroupName, string gatewayName, VpnGateway vpnGatewayParameters)
 {
     return(operations.CreateOrUpdateAsync(resourceGroupName, gatewayName, vpnGatewayParameters).GetAwaiter().GetResult());
 }