// Test case 2: Single padding
        final byte[] data2 = "abcd".getBytes();
        assertEquals("YWJjZA==", Base64Util.encode(data2));

        // Test case 3: Double padding
        final byte[] data3 = "abcde".getBytes();
        assertEquals("YWJjZGU=", Base64Util.encode(data3));

        // Test case 4: No padding
        final byte[] data4 = "abcdef".getBytes();
        assertEquals("YWJjZGVm", Base64Util.encode(data4));

        // Corresponds to a string of length 5 (10 bytes for UTF-16)
        PacUnicodeString pacString = new PacUnicodeString((short) 10, (short) 20, 100);
        String testString = "abcde";

        // The check method should return the same string instance
        String result = pacString.check(testString);
        assertSame(testString, result, "The check method should return the original string on success.");

		{"DATA", "·D(SB)/5,$0.0", "bad float size for DATA argument: 5"},
		{"DATA", "·E(SB)/4,$·A(SB)", "bad addr size for DATA argument: 4"},
		{"DATA", "·F(SB)/8,$·A(SB)", ""},
		{"DATA", "·G(SB)/5,$\"abcde\"", ""},
		{"GLOBL", "", "expect two or three operands for GLOBL"},
		{"GLOBL", "0,1", "GLOBL symbol \"<erroneous symbol>\" must be a symbol(SB)"},
		{"GLOBL", "@B(SB), 0", "expected '(', found B"}, // Issue 23580.

    return new CharSource() {
      @Override
      public Reader openStream() {
        return new StringReader(text);
      }
    };
  }

  public void testSkip() throws Exception {
    String begin = "abcde";
    String end = "fghij";
    Reader joinedReader = CharSource.concat(newCharSource(begin), newCharSource(end)).openStream();

    String expected = begin + end;
    assertEquals(expected.charAt(0), joinedReader.read());

  public void testReadEmptyString() throws IOException {
    assertReadsCorrectly("");
  }

  public void testReadsStringsCorrectly() throws IOException {
    assertReadsCorrectly("abc");
    assertReadsCorrectly("abcde");
    assertReadsCorrectly("abcdefghijkl");
    assertReadsCorrectly(
        ""
            + "abcdefghijklmnopqrstuvwxyz\n"
            + "ABCDEFGHIJKLMNOPQRSTUVWXYZ\r"
            + "0123456789\r\n"

  public void testReadEmptyString() throws IOException {
    assertReadsCorrectly("");
  }

  public void testReadsStringsCorrectly() throws IOException {
    assertReadsCorrectly("abc");
    assertReadsCorrectly("abcde");
    assertReadsCorrectly("abcdefghijkl");
    assertReadsCorrectly(
        ""
            + "abcdefghijklmnopqrstuvwxyz\n"
            + "ABCDEFGHIJKLMNOPQRSTUVWXYZ\r"
            + "0123456789\r\n"