The problem is already mentioned in code, see [wrapper.go#L97-L98](https://github.com/gopherjs/websocket/blob/c5adc75713fca342f299c521e8e2f4419de262d9/wrapper.go#L97-L98). I can confirm the issue. `Send` returns nil error, but there is a `WebSocket is already in CLOSING or CLOSED state.` error in the console.  Any ideas on how we can fix this?