code: public VirtualWANInner beginCreateOrUpdate(String resourceGroupName, String virtualWANName, VirtualWANInner wANParameters) {
          return beginCreateOrUpdateWithServiceResponseAsync(resourceGroupName, virtualWANName, wANParameters).toBlocking().single().body();
      }
docs: Creates a VirtualWAN resource if it doesn't exist else updates the existing VirtualWAN.
  
  @param resourceGroupName The resource group name of the VirtualWan.
  @param virtualWANName The name of the VirtualWAN being created or updated.
  @param wANParameters Parameters supplied to create or update VirtualWAN.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the VirtualWANInner object if successful.