throw new UnsupportedOperationException();
    }
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a
   * specified function to each item in an {@code Iterable} of values. Each value will be stored as
   * a value in the resulting multimap, yielding a multimap with the same size as the input

    Enumeration<Integer> enumer = enumerate(1, 2, 3);
    Iterator<Integer> iter = Iterators.forEnumeration(enumer);

    assertTrue(iter.hasNext());
    assertEquals(1, (int) iter.next());
    assertTrue(iter.hasNext());
    assertEquals(2, (int) iter.next());
    assertTrue(iter.hasNext());
    assertEquals(3, (int) iter.next());
    assertFalse(iter.hasNext());
  }

  public void testAsEnumerationEmpty() {