1) You may have observed that the add(E e) and remove(int index) methods are marked as optional operations. Briefly discuss the benefits vs. pitfalls of this design decision.

2) Consider this quote from the java.util.List description:

Some list implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements.

Briefly discuss the benefits vs. pitfalls of this design decision.

http://web.cse.ohio-state.edu/software/2231/web-sw2/assignments/homeworks/java-util-list.html