src/vs/editor/common/cursor/cursorMoveOperations.ts/MoveOperations/left
class MoveOperations:	private static left(config: CursorConfiguration, model: ICursorSimpleModel, position: Position): CursorPosition {
		const pos = config.stickyTabStops
			? MoveOperations.leftPositionAtomicSoftTabs(model, position, config.tabSize)
			: MoveOperations.leftPosition(model, position);
		return new CursorPosition(pos.lineNumber, pos.column, 0);
	}