private void When(DocumentHandleAttached e)
 {
     _handles.Add(e.Handle);
 }
 public void On(DocumentHandleAttached e)
 {
     _documents.FindAndModify(e, (DocumentDescriptorId)e.AggregateId, d => d.AddHandle(e.Handle));
 }
 private void When(DocumentHandleAttached e)
 {
     _handles.Add(e.Handle);
 }