Integer[] starting = Arrays.copyOf(array1, array1.length);
    Integer[] array2 = Arrays.copyOf(array1, array1.length);
    Object[] reference = list.toArray(array1);

    Object[] target = ObjectArrays.toArrayImpl(list, array2);

    assertEquals(reference.getClass(), target.getClass());
    assertTrue(Arrays.equals(reference, target));

    assertThat(Bytes.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Bytes.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Bytes.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Bytes.concat(ARRAY1, ARRAY1, ARRAY1))
        .isEqualTo(new byte[] {(byte) 1, (byte) 1, (byte) 1});
    assertThat(Bytes.concat(ARRAY1, ARRAY234))

    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(Doubles.concat(ARRAY1, ARRAY234)).isEqualTo(new double[] {1.0, 2.0, 3.0, 4.0});
  }

    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});
    assertThat(Ints.concat(ARRAY1, ARRAY234))

    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))
        .isEqualTo(new char[] {(char) 1, (char) 1, (char) 1});
    assertThat(Chars.concat(ARRAY1, ARRAY234))

    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(Longs.concat(ARRAY1, ARRAY234)).isEqualTo(new long[] {1L, 2L, 3L, 4L});
  }

    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(Doubles.concat(ARRAY1, ARRAY234)).isEqualTo(new double[] {1.0, 2.0, 3.0, 4.0});
  }

    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(Shorts.concat(ARRAY1, ARRAY234))

    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(Floats.concat(ARRAY1, ARRAY234)).isEqualTo(new float[] {1.0f, 2.0f, 3.0f, 4.0f});
  }

    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(Floats.concat(ARRAY1, ARRAY234)).isEqualTo(new float[] {1.0f, 2.0f, 3.0f, 4.0f});
  }