code: public Observable<Void> resetVpnClientSharedKeyAsync(String resourceGroupName, String virtualNetworkGatewayName) {
          return resetVpnClientSharedKeyWithServiceResponseAsync(resourceGroupName, virtualNetworkGatewayName).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Resets the VPN client shared key of the virtual network gateway in the specified resource group.
  
  @param resourceGroupName The name of the resource group.
  @param virtualNetworkGatewayName The name of the virtual network gateway.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request