lxn/walk — comment on commit 8f5a1176964a711a6394c08f454a5914d3175ccc
File: cancelevent.go line 19
By bsiegert:

I think that this is the wrong approach. If you call e.g. Detach(1), then the old event 2 becomes the new 1, i.e. the handles become invalid. It would be better to write this as

```go
e.handlers[handle] = nil
```

and then check for nil before calling a handler.