return new SampleElements<>(
          mapEntry("one", collectionOf(10000)),
          mapEntry("two", collectionOf(-2000)),
          mapEntry("three", collectionOf(300)),
          mapEntry("four", collectionOf(-40)),
          mapEntry("five", collectionOf(5)));
    }

    // javac7 can't infer the type parameters correctly in samples()
    private static Collection<Integer> collectionOf(int item) {

    Iterator<String> iterator = asList("one", "two", "three", "four", "five").iterator();
    try {
      Iterators.getOnlyElement(iterator);
      fail();
    } catch (IllegalArgumentException expected) {
      assertThat(expected)
          .hasMessageThat()
          .isEqualTo("expected one element but was: <one, two, three, four, five>");
    }
  }

    Set<Object> zero = ImmutableSet.of();
    Set<Set<Object>> one = powerSet(zero);
    Set<Set<Set<Object>>> two = powerSet(one);
    Set<Set<Set<Set<Object>>>> four = powerSet(two);
    Set<Set<Set<Set<Set<Object>>>>> sixteen = powerSet(four);
    Set<Set<Set<Set<Set<Set<Object>>>>>> sixtyFiveThousandish = powerSet(sixteen);
    assertEquals(1 << 16, sixtyFiveThousandish.size());

        new boolean[] {false, true, false, true, false, true, false},
        2,
        0,
        3,
        new boolean[] {true, false, false, true, false, true, false});

    // Rotate the last four elements
    testRotate(
        new boolean[] {false, true, false, true, false, true, false},
        -6,
        3,
        7,
        new boolean[] {false, true, false, true, false, true, false});

        new boolean[] {false, true, false, true, false, true, false},
        2,
        0,
        3,
        new boolean[] {true, false, false, true, false, true, false});

    // Rotate the last four elements
    testRotate(
        new boolean[] {false, true, false, true, false, true, false},
        -6,
        3,
        7,
        new boolean[] {false, true, false, true, false, true, false});

    testRotate(new short[] {0, 1, 2, 3, 4, 5, 6}, 1, 0, 3, new short[] {2, 0, 1, 3, 4, 5, 6});
    testRotate(new short[] {0, 1, 2, 3, 4, 5, 6}, 2, 0, 3, new short[] {1, 2, 0, 3, 4, 5, 6});

    // Rotate the last four elements
    testRotate(new short[] {0, 1, 2, 3, 4, 5, 6}, -6, 3, 7, new short[] {0, 1, 2, 5, 6, 3, 4});
    testRotate(new short[] {0, 1, 2, 3, 4, 5, 6}, -5, 3, 7, new short[] {0, 1, 2, 4, 5, 6, 3});

    testRotate(new float[] {0, 1, 2, 3, 4, 5, 6}, 1, 0, 3, new float[] {2, 0, 1, 3, 4, 5, 6});
    testRotate(new float[] {0, 1, 2, 3, 4, 5, 6}, 2, 0, 3, new float[] {1, 2, 0, 3, 4, 5, 6});

    // Rotate the last four elements
    testRotate(new float[] {0, 1, 2, 3, 4, 5, 6}, -6, 3, 7, new float[] {0, 1, 2, 5, 6, 3, 4});
    testRotate(new float[] {0, 1, 2, 3, 4, 5, 6}, -5, 3, 7, new float[] {0, 1, 2, 4, 5, 6, 3});

  public static final Integer zero = 0;
  public static final Integer one = 1;
  public static final Integer two = 2;
  public static final Integer three = 3;
  public static final Integer four = 4;
  public static final Integer five = 5;
  public static final Integer six = 6;
  public static final Integer seven = 7;
  public static final Integer eight = 8;
  public static final Integer nine = 9;

  public static <T extends @Nullable Object> Iterable<T> concat(
      Iterable<? extends T> a, Iterable<? extends T> b, Iterable<? extends T> c) {
    return FluentIterable.concat(a, b, c);
  }

  /**
   * Combines four iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements in {@code a}, followed by the elements in {@code b}, followed by the

        4,
        "four");
    assertMapEquals(
        ImmutableBiMap.of("one", 1, "two", 2, "three", 3, "four", 4, "five", 5),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",
        4,
        "five",
        5);
    assertMapEquals(
        ImmutableBiMap.of("one", 1, "two", 2, "three", 3, "four", 4, "five", 5).inverse(),
        1,
        "one",