the question as below

Describe the garbage collection method for the SinglyLinkedList structure, and give the line number of the code presented in Figure 4.15 of the text that accomplishes (i.e., actually initiates) the garbage collection.

4.15

And this the rest as

ublic class SinglyLinkedList Node h; i list header rivate public SinglyLinkedList 3. h new Node ()Odny node h.1null; h.next null; public boolean insert(Listing newisting) 9. Node nnew Node (); f (n -null) // out of memory 10. return false; else n.next h.next; 14 15 n.1 newListing.deepCopy ( ); return true; 17.) 19. public Listing fetch(String targetkey) 20. Node p h.next; 21 while(p null & (p.1.compareTo(targetkey)0)) pp.next; 24. 25 26. 27 28. 29. 30, return p.1.deepcopy): else return null; public boolean delete(String targetkey) { Node q h; Node ph.next; while(p nu1l & I(p.1.compareTo(targetKey)0 32. 34 P p.next; if (p null) q.next p.next; 38, return true; else return false; 42. public boolean update(String targetkey, Listing newlisting) 4s, if (delete(targetKey) false) return false; 47 eise if (insert (newListing) false) return false; return true; d4.15 The implementation of the Sinety Liked