Please complete all parts shown as "TODO" * If list is already empty, then do nothing * No action is performed on the elements. * */ a0verride public void removeAll() // TOD0 \} /** * Remove elem at index * Return the removed element * Throws Index0utOfBoundsException if passed index is invalid. */ (a0verride public E removeIndex(int index) \{ // TOD0 return null; \} /* *.