assertThrows(IllegalArgumentException.class, () -> Doubles.ensureCapacity(ARRAY1, 1, -1));
  }

  @GwtIncompatible // Double.toString returns different value in GWT.
  public void testJoin() {
    assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Doubles.join(",", 1.0, 2.0)).isEqualTo("1.0,2.0");

    assertThrows(IllegalArgumentException.class, () -> Longs.ensureCapacity(ARRAY1, -1, 1));
    assertThrows(IllegalArgumentException.class, () -> Longs.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testJoin() {
    assertThat(Longs.join(",", EMPTY)).isEmpty();
    assertThat(Longs.join(",", ARRAY1)).isEqualTo("1");
    assertThat(Longs.join(",", 1L, 2L)).isEqualTo("1,2");

    assertThrows(IllegalArgumentException.class, () -> Shorts.ensureCapacity(ARRAY1, -1, 1));
    assertThrows(IllegalArgumentException.class, () -> Shorts.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testJoin() {
    assertThat(Shorts.join(",", EMPTY)).isEmpty();
    assertThat(Shorts.join(",", ARRAY1)).isEqualTo("1");
    assertThat(Shorts.join(",", (short) 1, (short) 2)).isEqualTo("1,2");

    assertThrows(IllegalArgumentException.class, () -> Floats.ensureCapacity(ARRAY1, 1, -1));
  }

  @GwtIncompatible // Float.toString returns different value in GWT.
  public void testJoin() {
    assertThat(Floats.join(",", EMPTY)).isEmpty();
    assertThat(Floats.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Floats.join(",", 1.0f, 2.0f)).isEqualTo("1.0,2.0");

    assertThrows(IllegalArgumentException.class, () -> Ints.ensureCapacity(ARRAY1, -1, 1));
    assertThrows(IllegalArgumentException.class, () -> Ints.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testJoin() {
    assertThat(Ints.join(",", EMPTY)).isEmpty();
    assertThat(Ints.join(",", ARRAY1)).isEqualTo("1");
    assertThat(Ints.join(",", (int) 1, (int) 2)).isEqualTo("1,2");

    assertThrows(IllegalArgumentException.class, () -> Floats.ensureCapacity(ARRAY1, 1, -1));
  }

  @GwtIncompatible // Float.toString returns different value in GWT.
  public void testJoin() {
    assertThat(Floats.join(",", EMPTY)).isEmpty();
    assertThat(Floats.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Floats.join(",", 1.0f, 2.0f)).isEqualTo("1.0,2.0");