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(Doubles.concat(ARRAY1, ARRAY1, ARRAY1)).isEqualTo(new double[] {1.0, 1.0, 1.0});

    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))
        .isEqualTo(new int[] {(int) 1, (int) 1, (int) 1});

    assertDoesntActuallyTrim(iia2);
  }

  private static void assertActuallyTrims(ImmutableIntArray iia) {
    ImmutableIntArray trimmed = iia.trimmed();
    assertThat(trimmed).isNotSameInstanceAs(iia);

    // Yes, this is apparently how you check array equality in Truth
    assertThat(trimmed.toArray()).isEqualTo(iia.toArray());
  }

    assertDoesntActuallyTrim(iia2);
  }

  private static void assertActuallyTrims(ImmutableDoubleArray iia) {
    ImmutableDoubleArray trimmed = iia.trimmed();
    assertThat(trimmed).isNotSameInstanceAs(iia);

    // Yes, this is apparently how you check array equality in Truth
    assertThat(trimmed.toArray()).isEqualTo(iia.toArray());
  }

    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);
    assertThat(Booleans.concat(ARRAY_FALSE, ARRAY_FALSE, ARRAY_FALSE))
        .isEqualTo(new boolean[] {false, false, false});

    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(Doubles.concat(ARRAY1, ARRAY1, ARRAY1)).isEqualTo(new double[] {1.0, 1.0, 1.0});

    assertThat(Longs.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Longs.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Longs.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Longs.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Longs.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Longs.concat(ARRAY1, ARRAY1, ARRAY1)).isEqualTo(new long[] {1L, 1L, 1L});

    assertThat(Shorts.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Shorts.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Shorts.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Shorts.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Shorts.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Shorts.concat(ARRAY1, ARRAY1, ARRAY1))
        .isEqualTo(new short[] {(short) 1, (short) 1, (short) 1});

    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);
    assertThat(Floats.concat(ARRAY1, ARRAY1, ARRAY1)).isEqualTo(new float[] {1.0f, 1.0f, 1.0f});

    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))
        .isEqualTo(new int[] {(int) 1, (int) 1, (int) 1});