code: protected void removeEntry(T entry) {
          T prev = entry.getPrev();
          T next = entry.getNext();
          if (prev != null) {
              prev.setNext(next);
          } else {
              head = next;
          }
          if (next != null) {
              next.setPrev(prev);
          } else {
              last = prev;
          }
          size--;
      }
docs: Removes an entry from the list.
  
  @param entry
  the entry to remove.