Assume that we would like an iterator that implements the isValid, advance, and retrieve set of methods, but all we have is the standard java.util.Iterator interface. a. What pattern describes the...

Assume that we would like an iterator that implements the isValid, advance, and retrieve set of methods, but all we have is the standard java.util.Iterator interface.

a. What pattern describes the problem we are trying to solve?

 b. Design a BetterIterator class, and then implement it in terms of java.util.Iterator.