code: public ServiceFuture<ExpressRouteConnectionInner> beginCreateOrUpdateAsync(String resourceGroupName, String expressRouteGatewayName, String connectionName, ExpressRouteConnectionInner putExpressRouteConnectionParameters, final ServiceCallback<ExpressRouteConnectionInner> serviceCallback) {
          return ServiceFuture.fromResponse(beginCreateOrUpdateWithServiceResponseAsync(resourceGroupName, expressRouteGatewayName, connectionName, putExpressRouteConnectionParameters), serviceCallback);
      }
docs: Creates a connection between an ExpressRoute gateway and an ExpressRoute circuit.
  
  @param resourceGroupName The name of the resource group.
  @param expressRouteGatewayName The name of the ExpressRoute gateway.
  @param connectionName The name of the connection subresource.
  @param putExpressRouteConnectionParameters Parameters required in an ExpressRouteConnection PUT operation.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object