[Scala] Adding samples from week 7 lectures
[Scala] Adding samples from week 7 lectures

afronski/playground-notes,keshavbashyal/playground-notes,M4573R/playground-notes,M4573R/playground-notes,afronski/playground-notes,afronski/playground-notes,afronski/playground-notes,M4573R/playground-notes,afronski/playground-notes,afronski/playground-notes,afronski/playground-notes,M4573R/playground-notes,keshavbashyal/playground-notes,keshavbashyal/playground-notes,keshavbashyal/playground-notes,keshavbashyal/playground-notes,M4573R/playground-notes,M4573R/playground-notes,M4573R/playground-notes,afronski/playground-notes,keshavbashyal/playground-notes,keshavbashyal/playground-notes,M4573R/playground-notes,keshavbashyal/playground-notes