How to handle events

using Microsoft.Practices.CompositeUI.EventBroker;
using Artech.Architecture.Common.Events;
using Artech.Architecture.Common.Objects;

[EventSubscription(ArchitectureEvents.AfterOpenKB)]
public void OnAfterOpenKB(object sender, KBEventArgs args)
{
}
[EventSubscription(ArchitectureEvents.AfterCloseKB)]
public void OnAfterCloseKB(object sender, EventArgs args)
{
}
[EventSubscription(ArchitectureEvents.AfterDeleteKBObject)]
public void OnAfterDeleteKBObject(object sender, KBObjectEventArgs args)
{
KBObject obj = args.KBObject;
}
[EventSubscription(ArchitectureEvents.BeforeSaveKBObject)]
public void OnBeforeSaveKBObject(object sender, KBObjectEventArgs args)
{
KBObject obj = args.KBObject;
}
[EventSubscription(UIDocumentEvents.BeforeOpenDocument)]
public void OnBeforeOpenDocument(object sender, DocumentCancelEventArgs args)
{
KBObject obj = args.Document.Object;
}