assert that there are no more than 5 touches per touch state
investigate how the system interpolates between multiple touches at different states (i.e. between touches at points [p1, p2] and [p3, p4] does the touch at p1 move to p3 simply based on its index in the array or what)
[ ] discrete gestures with multiple touches (i.e. a multiple tap gesture)
A custom gesture is a gesture other than tapping/touching-and-holding (at a single point), dragging/swiping (in straight lines), or rotating.
To simulate arbitrary gestures, we would need to be able to simulate touches directly, as occurring at specific points, at particular times.