void OnDropPayload ( [ISceneOutlinerTreeItem](API\Editor\SceneOutliner\ISceneOutlinerTreeItem) & DropTarget, const [FSceneOutlinerDragDropPayload](API\Editor\SceneOutliner\FSceneOutlinerDragDropPayload) & Payload, const [FSceneOutlinerDragValidationInfo](API\Editor\SceneOutliner\FSceneOutlinerDragValidationInfo) & ValidationInfo ) const