问什么是领域事件的真实世界，生产级案例(理解为同一有限上下文和过程中的事件)？

EN

public CategoryRenamed : DomainEvent
{
    public Category Category { get; }

    internal CategoryRenamed(Category category)
    {
        this.Category = category;
    }
}

public CategoryRenamedHandler : IDomainEventHandler<CategoryRenamed>
{
    public CategoryRenamedHandler(CategoryRenamed domainEvent)
    {
        string proposedName = domainEvent.Category.Name;

        // query database to ensure that proposedName is not already in use
        if (inUse)
            throw new Exception($"Name {proposedName} already in use." ;
    }
}

public abstract class Entity
{
    List<DomainEvent> _domainEvents = new List<DomainEvent>();

    protected AddDomainEvent(DomainEvent domainEvent)
    {
        _domainEvents.Add(domainEvent);
    }

    public List<DomainEvent> DomainEvents => _domainEvents;
}

public class Category : Entity
{
    public Guid Id { get; private set; }
    public string Name { get; private set; }

    public Category(Guid id, string name)
    {
        Id = id;
        SetName(name);
    }

    public Rename(string name)
    {
        SetName(name);
    }

    void SetName(string name)
    {
        // Local Invariants
        if (string.IsNullOrWhitespace(name))
            throw new Exception("Invalid name");

        Name = name;

        // Add a domain event for the infrastructure to process
        AddDomainEvent(new CategoryRenamed(this));
    }
}

public class AddCategoryCommand
{
    public Guid Id { get; set; }
    public string Name { get; set; }
}

public class CommandHandler : ICommandHandler<AddCategoryCommand>
{
    readonly ICategoryRepository _categoryRepository;

    public CommandHandler(ICategoryRepository categoryRepository)
    {
        _categoryRepository = categoryRepository;
    }

    public void HandleCommand(AndCategoryCommand command)
    {
        Category newCategory = new(command.Id, command.Name);

        // Check for domain events before committing to repository
        DomainEventDispatcher.DispatchEvents(newCategory.DomainEvents);
        // Dispatcher will find the CategoryRenamed event and send 'in-process'
        // to CategoryRenamedHandler
        // If name was is in use an error will be thrown by the handler (see above)

        _categoryRepository.Add(newCategory);
    }
}