@Test
public void aa() {
  Collection<String> fruits;
  Iterator<String> fruitIterator;

  fruitIterator = mock(Iterator.class);
  when(fruitIterator.hasNext()).thenReturn(true, true, true, false);
  when(fruitIterator.next()).thenReturn("Apple")
      .thenReturn("Banana").thenReturn("Pear");

  fruits = mock(Collection.class);
  when(fruits.iterator()).thenReturn(fruitIterator);

  // this doesn't work (it doesn't print anything)
  fruits.forEach(f -> System.out.println(f));

  // this works fine
  /*
  int iterations = 0;
  for (String fruit : fruits) {
    System.out.println(fruit);
  }
  */
}