assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());
    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3).iterator()).read());
    assertEquals(expected.length, ByteSource.concat(b1, b2, b3).size());
    assertFalse(ByteSource.concat(b1, b2, b3).isEmpty());

      protected Iterator<Integer> newTargetIterator() {
        return Iterators.concat();
      }
    }.test();
  }

  @GwtIncompatible // slow (~5s)
  public void testConcatOneEmptyIteratorYieldsEmpty() {
    new EmptyIteratorTester() {
      @Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterators.concat(iterateOver());
      }
    }.test();
  }

  }

  public void testConcat() {
    assertThat(Doubles.concat()).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Doubles.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Doubles.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);

    assertThat(Chars.concat()).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Chars.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1, ARRAY1, ARRAY1))

   * iterator supports it.
   *
   * <p><b>Java 8+ users:</b> The {@code Stream} equivalent of this method is {@code
   * Stream.concat(a, b)}.
   */
  public static <T extends @Nullable Object> Iterable<T> concat(
      Iterable<? extends T> a, Iterable<? extends T> b) {
    return FluentIterable.concat(a, b);
  }

  /**
   * Combines three iterables into a single iterable. The returned iterable has an iterator that

  public void testConcat() {
    assertThat(Booleans.concat()).isEqualTo(EMPTY);
    assertThat(Booleans.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Booleans.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Booleans.concat(ARRAY_FALSE)).isEqualTo(ARRAY_FALSE);
    assertThat(Booleans.concat(ARRAY_FALSE)).isNotSameInstanceAs(ARRAY_FALSE);
    assertThat(Booleans.concat(EMPTY, ARRAY_FALSE, EMPTY)).isEqualTo(ARRAY_FALSE);

  }

  public void testConcat() {
    assertThat(Doubles.concat()).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Doubles.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Doubles.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);

    assertThat(Ints.concat()).isEqualTo(EMPTY);
    assertThat(Ints.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Ints.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Ints.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Ints.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Ints.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Ints.concat(ARRAY1, ARRAY1, ARRAY1))

      protected Iterator<Integer> newTargetIterator() {
        return Iterators.concat();
      }
    }.test();
  }

  @GwtIncompatible // slow (~5s)
  public void testConcatOneEmptyIteratorYieldsEmpty() {
    new EmptyIteratorTester() {
      @Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterators.concat(iterateOver());
      }
    }.test();
  }

  }

  public void testConcat() {
    assertThat(Floats.concat()).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Floats.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Floats.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);