src/vs/editor/contrib/dnd/browser/dnd.ts/DragAndDropController/showAt
class DragAndDropController:	public showAt(position: Position): void {
		let newDecorations: IModelDeltaDecoration[] = [{
			range: new Range(position.lineNumber, position.column, position.lineNumber, position.column),
			options: DragAndDropController._DECORATION_OPTIONS
		}];

		this._dndDecorationIds = this._editor.deltaDecorations(this._dndDecorationIds, newDecorations);
		this._editor.revealPosition(position, ScrollType.Immediate);
	}