Defines a map that can be iterated directly without needing to create an entry set.

A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or use Map Entry objects.

IterableMap<String,Integer> map = new HashedMap<String,Integer>();
MapIterator<String,Integer> it = map.mapIterator();
while (it.hasNext()) {
  String key = it.next();
  Integer value = it.getValue();
  it.setValue(value + 1);
}