4.2 Show the list configuration resulting from each series of list operations using the List ADT of Figure 4.1. Assume that lists Ll and L2 are empty at the beginning of each series. Show where the current position is in the list. (a) L1.append (10); L1 . append (20) ; L1 . append (15) ; (b) L2.append (1o) L2 . append (20 ) ; L2 . append (15) ; L2.moveToStart ( ) ; L2. insert (39) ; L2. next () ; L2. insert (12)