> It definitely never does anything behind-the-scenes or behind-your-back. Actually that's a bit of a lie, because of the economy of primary device context ref

> It definitely never does anything behind-the-scenes or behind-your-back. Actually that's a bit of a lie, because of the economy of primary device context reference counts (it's quite annoying if you need to do it well and not leak resources) and the context stack. So, let's say it does as little as possible behind the scenes... :-(