OptionalcollapsedContainers drawn as a single box.
OptionaldirectionLayers run left→right ("right", default) or top→bottom ("down").
Size of a transition's label (real orientation).
The size a state needs for its own content. Leaves (and collapsed containers): the whole box. Expanded containers: their header (name and anything listed with it); the layout adds room for the children.
OptionalspacingOverride some of the default gaps.
Input to
layoutChart: how big things are, and which way to lay them out.