<@U0QKQ7H3R> One thing I ran into is when trying t...

# gui

[t3wad]

@nfrankel One thing I ran into is when trying to use something like verticalLayout() inside a CustomComponent, which I believe only gets its content via constructor or with a protected setCompositionRoot(), so addTo() fails. I ended up doing the following:

container is ComponentContainer -> container.addComponent(this)
        container is CustomComponent -> Unit//do nothing, setCompositionRoot is not exposed, rely on caller to set it
        else -> throw IllegalArgumentException("Cannot add $this to $container")