throw new AssertionFailedError("Don't iterate me!");
          }
        };
    assertEquals(5, FluentIterable.from(collection).size());
  }

  public void testContains_nullSetYes() {
    Iterable<String> set = newHashSet("a", null, "b");
    assertTrue(FluentIterable.from(set).contains(null));
  }

  public void testContains_nullSetNo() {