The hit leaf scene node. Interaction templates are resolved from its
userData.attrs, walking up to the nearest ancestor that carries one.
Reported layer path — outermost kind=partition wrapper if any.
Scene node elementIndex is local to (the part_<i> leaf under a partition).
Element index within the hit leaf.
The element's label, or null when it has none.
The element's machine-readable key, or null when it has none (#1917).
Canvas-local cursor position the pick was taken at, in CSS pixels.
A picked element, as much of it as a click needs.