interface in UnityEditor.Experimental.UIElements.GraphView
マニュアルに切り替えるSelectable interface.
| HitTest | See if point is on target. |
| IsSelectable | Check if element is selectable. |
| IsSelected | Check if element is selected. |
| Overlaps | Check if selection overlaps rectangle. |
| Select | Select element. |
| Unselect | Deselect element. |