Activities of "jack"

At what point is called the AbpDbContext.Initialize() method?

    public virtual void Initialize()
    {
        Database.Initialize(false);
        this.SetFilterScopedParameterValue(AbpDataFilters.MustHaveTenant, AbpDataFilters.Parameters.TenantId, AbpSession.TenantId ?? 0);
        this.SetFilterScopedParameterValue(AbpDataFilters.MayHaveTenant, AbpDataFilters.Parameters.TenantId, AbpSession.TenantId);
    }

and why do you use Singleton rather than dependency injection? protected AbpDbContext() { Logger = NullLogger.Instance; AbpSession = NullAbpSession.Instance; EntityChangeEventHelper = NullEntityChangeEventHelper.Instance; }

why not protected AbpDbContext(ILogger,IAbpSession) ?