Prindl

I added basic filter support into html to canvas. https://github.com/niklasvh/html2canvas/pull/1763

I'm thinking the reason for your error during the shutdown might be that you are trying to close an already closed channel. Are you really using separate [processes](https://docs.python.org/3/library/multiprocessing.html) or are...

So the function that you are passing to the `multiprocessing.Process` object creates the instance of the `VectorBus`? In that case I don't see why it should not work... However, when...