src/vs/editor/common/commands/surroundSelectionCommand.ts/CompositionSurroundSelectionCommand/computeCursorState
class CompositionSurroundSelectionCommand:	public computeCursorState(model: ITextModel, helper: ICursorStateComputerData): Selection {
		const inverseEditOperations = helper.getInverseEditOperations();
		const opRange = inverseEditOperations[0].range;

		return new Selection(
			opRange.endLineNumber,
			opRange.startColumn,
			opRange.endLineNumber,
			opRange.endColumn - this._charAfter.length
		);
	}