code: public void clear() {
          Node<T> node = head.next, next;
          size = 0;
          head.reset(); // Clearing references.
          tail = head;
          iterator.currentNode = head;
          while (node != null) {
              next = node.next;
              node.free(pool);
              node = next;
          }
      }
docs: Removes all elements of the list. Frees all nodes to the pool.