Iterator.next() is ignored for List<Value<T>>

This code produces an endless loop:

```
List<Value<Long>> releases = entity.getList("releases");
System.out.println(releases.size());    // prints 1 

while (releases.iterator().hasNext()) {
    Value<Long> value = releases.iterator().next();
    System.out.println(value.get());   // prints correct value over and over
}

```
