Represents the object of the
onCheckChange event (see example).
The item that is selected or deselected.
The hierarchical index of the item. The indices are zero-based.
The first root item has a
0 (zero) index. If the first root item has children, the first child acquires a
0_0 index and the second acquires a
A native DOM event.
A React Synthetic Event.
An event target.