securityDescriptorBytes[21] = 0; // sbz1
        securityDescriptorBytes[22] = 8; // ACL size (low byte)
        securityDescriptorBytes[23] = 0; // ACL size (high byte)
        securityDescriptorBytes[24] = 0; // ACE count (low byte) - 0 ACEs
        securityDescriptorBytes[25] = 0; // ACE count (high byte)
        securityDescriptorBytes[26] = 0; // sbz2 (low byte)

    assertSame(sb1FromIterator, joiner.appendTo(sb1FromIterator, set));
    assertEquals(0, sb1FromIterator.length());

    StringBuilder sb2 = new StringBuilder();
    assertSame(sb2, joiner.appendTo(sb2, array));
    assertEquals(0, sb2.length());

    try {
      joiner.appendTo(NASTY_APPENDABLE, set);
    } catch (IOException e) {
      throw new AssertionError(e);
    }

    try {

        StringBuilder sb2 = new StringBuilder("second");
        String result = StringUtil.join(",", sb1, sb2);
        assertEquals("first,second", result);
    }

    @Test
    @DisplayName("Should handle StringBuffer as CharSequence")
    void testJoinWithStringBuffer() {
        StringBuffer sb1 = new StringBuffer("alpha");
        StringBuffer sb2 = new StringBuffer("beta");

        response = spy(response);
        when(response.getHeaderStart()).thenReturn(0);

        // Write minimal SecurityDescriptor header (20 bytes)
        buffer[20] = 1; // Revision
        buffer[21] = 0; // Sbz1
        SMBUtil.writeInt2(0x8004, buffer, 22); // Control flags
        SMBUtil.writeInt4(0, buffer, 24); // Owner offset
        SMBUtil.writeInt4(0, buffer, 28); // Group offset

application/x-ibooks+zip=ibooks\n\
text/plain=txt\n\
application/rtf=rtf\n\
application/vnd.ms-htmlhelp=chm\n\
application/zip=zip\n\
application/x-7z-comressed=7z\n\
application/x-bzip=bz\n\
application/x-bzip2=bz2\n\
application/x-tar=tar\n\
application/x-rar-compressed=rar\n\
video/3gp=3gp\n\
video/3g2=3g2\n\
video/x-msvideo=avi\n\
video/x-flv=flv\n\
video/mpeg=mpeg\n\
video/mp4=mp4\n\
video/ogv=ogv\n\

     * application/rtf=rtf<br>
     * application/vnd.ms-htmlhelp=chm<br>
     * application/zip=zip<br>
     * application/x-7z-comressed=7z<br>
     * application/x-bzip=bz<br>
     * application/x-bzip2=bz2<br>
     * application/x-tar=tar<br>
     * application/x-rar-compressed=rar<br>
     * video/3gp=3gp<br>
     * video/3g2=3g2<br>
     * video/x-msvideo=avi<br>
     * video/x-flv=flv<br>