This can be null if the event is not directly tied to a specific IInteractorView instance (e.g., some UI events might only have a _pointerId).
GameObject _source[Get]
The GameObject that is the primary target or source of the interaction (e.g., the interactable object that was hovered or selected).
This can be null if the interaction source is not a GameObject or is not applicable.
int _pointerId[Get]
An identifier for UI pointer interactions, such as UnityEngine.EventSystems.PointerEventData.pointerId.
Defaults to -1 if not applicable or unknown. For non-UI interactions tied to an InteractorView, the IInteractorView.Identifier should be preferred if a unique ID is needed.