Here unsystematic play with linked list structure Object Oriented style. If you have performance critical code, please do not use this but use the superb faster than list blist module (including sorted versions of main data structures).
As OO newbie (though with some 30 years of other programming), I wanted to get some practice and remind myself on the basics once more.
Hope you find this code interesting. Main program testing routines are 'ad hoc' not seriously planned 'cover the corners' testing.