*/
    public void testDecode_Null() throws Exception {
        final byte[] result = Base64Util.decode(null);
        assertNull("Null should return null", result);
    }

    /**
     * Test encode/decode round trip with various data
     *
     * @throws Exception
     */
    public void testEncodeDecode_RoundTrip() throws Exception {
        // Test with ASCII text
        final String text = "Hello, World!";

    This is useful when we use ConstrainedDecimal to represent Numeric(x,0)
    where an integer (but not int typed) is used. Encoding this as a float
    results in failed round-tripping between encode and parse.
    Our Id type is a prime example of this.

    >>> decimal_encoder(Decimal("1.0"))
    1.0

    >>> decimal_encoder(Decimal("1"))
    1

  }

  public void testToByteArrayAndFromByteArrayRoundTrip() {
    for (PairedStats pairedStats : ALL_PAIRED_STATS) {
      byte[] pairedStatsByteArray = pairedStats.toByteArray();

      // Round trip to byte array and back
      assertThat(PairedStats.fromByteArray(pairedStatsByteArray)).isEqualTo(pairedStats);
    }
  }

  public void testFromByteArray_withNullInputThrowsNullPointerException() {

  }

  public void testToByteArrayAndFromByteArrayRoundTrip() {
    for (PairedStats pairedStats : ALL_PAIRED_STATS) {
      byte[] pairedStatsByteArray = pairedStats.toByteArray();

      // Round trip to byte array and back
      assertThat(PairedStats.fromByteArray(pairedStatsByteArray)).isEqualTo(pairedStats);
    }
  }

  public void testFromByteArray_withNullInputThrowsNullPointerException() {

    assertSame(testEquivalence, map.keyEquivalence);
    assertSame(map.valueStrength().defaultEquivalence(), map.valueEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);

    assertSame(testEquivalence, map.keyEquivalence);
    assertSame(map.valueStrength().defaultEquivalence(), map.valueEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);

	reader := NewReader(&buf)
	hdr, err = reader.Next()
	if err != nil {
		t.Fatal(err)
	}
	if !maps.Equal(hdr.Xattrs, xattrs) {
		t.Fatalf("xattrs did not survive round trip: got %+v, want %+v",
			hdr.Xattrs, xattrs)
	}
}

func TestPaxHeadersSorted(t *testing.T) {
	fileinfo, err := os.Stat("testdata/small.txt")
	if err != nil {
		t.Fatal(err)
	}

key directly to its instructions. type blockExpanded struct { rounds int // Round keys, where only the first (rounds + 1) × (128 ÷ 32) words are used. enc [60]uint32 dec [60]uint32 } const ( // AES-128 has 128-bit keys, 10 rounds, and uses 11 128-bit round keys // (11×128÷32 = 44 32-bit words). // AES-192 has 192-bit keys, 12 rounds, and uses 13 128-bit round keys // (13×128÷32 = 52 32-bit words). // AES-256 has 256-bit keys, 14 rounds, and uses 15 128-bit round keys // (15×128÷32 = 60 32-bit words)....

    assertThat(map.valueEquivalence).isSameInstanceAs(testEquivalence);
    assertThat(map.keyEquivalence).isSameInstanceAs(map.keyStrength.defaultEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);

    assertThat(map.valueEquivalence).isSameInstanceAs(testEquivalence);
    assertThat(map.keyEquivalence).isSameInstanceAs(map.keyStrength.defaultEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);