behavior.cs

public class DemoBehavior : IPipelineBehavior<PlaceOrder, Unit>
{
    private readonly ILogger<DemoBehavior> _logger;

    public DemoBehavior(ILogger<DemoBehavior> logger)
    {
        _logger = logger;
    }

    public async Task<Unit> Handle(PlaceOrder request, CancellationToken cancellationToken, RequestHandlerDelegate<Unit> next)
    {
        _logger.LogInformation($"Handling {nameof(PlaceOrder)}");

        var response = await next();
        return response;
    }
}