The 1.4 version of the exam covers two new collections classes--LinkedHashMap and LinkedHashSet. One of the features that differentiates a LinkedHashMap from the older HashMap is the addition of the removeEldestEntry method. If you know that a LinkedHashMap is a good choice for the implementation of a cache then you would also know that LinkedHashMap declares a removeEldestEntry method.
The exam does not require memorization of the APIs for the collections classes. Instead, it requires you to select the best Collection implementation for a particular application. In this case, the removeEldestEntry method is the unique feature that makes the LinkedHashMap a good choice for use as a cache.
Having said the above, the real exam would be more likely to ask which class is the best choice for the implementation of a cache.
If Kathy or Bert reads this
thread, then it would interesting to see if they would like to comment on how the real exam covers the two new collections classes.