assertEquals(0, cap.getValue().length, "Optimistic token must be zero-length");
    }

    @ParameterizedTest
    @ValueSource(bytes = { 0x00, 0x7F, (byte) 0xFF })
    @DisplayName("initSecContext throws on invalid token type")
    void testInitSecContextInvalidTokenType(byte firstByte) throws Exception {
        SpnegoContext ctx = newContext();

        val codepointDelta = (b1 and 0xF shl 14) or (b2 shl 7) or b3
        sink.writeUtf8CodePoint(codePoint - codepointDelta)
      }

      in 80..95 -> {
        // Mapped inline as codePoint delta to add
        val b2 = ranges[rangesIndex + 2].code
        val b3 = ranges[rangesIndex + 3].code

        val codepointDelta = (b1 and 0xF shl 14) or (b2 shl 7) or b3

        byte[] buffer = new byte[100];
        int bufferIndex = 0;

        // Reserved bytes
        buffer[bufferIndex] = (byte) 0xFF;
        buffer[bufferIndex + 1] = (byte) 0xFF;
        buffer[bufferIndex + 2] = (byte) 0xFF;

        // Set fields with negative values (should be treated as unsigned)
        SMBUtil.writeInt4(-1, buffer, bufferIndex + 3); // Should be read as 0xFFFFFFFF

      encodings[0x1c] = encoding // File Separator
      encodings[0x1d] = encoding // Group Separator
      encodings[0x1e] = encoding // Record Separator
      encodings[0x1f] = encoding // Unit Separator
      encodings[0x7f] = encoding // Delete
    }

  fun nonAscii(encoding: Encoding) =
    apply {
      encodings[UNICODE_2] = encoding
      encodings[UNICODE_3] = encoding
      encodings[UNICODE_4] = encoding

        key8[0] = (byte) (key7[0] >> 1 & 0xff);
        key8[1] = (byte) (((key7[0] & 0x01) << 6 | (key7[1] & 0xff) >> 2 & 0xff) & 0xff);
        key8[2] = (byte) (((key7[1] & 0x03) << 5 | (key7[2] & 0xff) >> 3 & 0xff) & 0xff);
        key8[3] = (byte) (((key7[2] & 0x07) << 4 | (key7[3] & 0xff) >> 4 & 0xff) & 0xff);
        key8[4] = (byte) (((key7[3] & 0x0F) << 3 | (key7[4] & 0xff) >> 5 & 0xff) & 0xff);

        doAnswer(inv -> {
            byte[] b = inv.getArgument(0);
            int off = inv.getArgument(1);
            b[off] = (byte) 0xFF;
            return 1;
        }).when(raf).read(any(byte[].class), anyInt(), eq(1));
        assertTrue(raf.readBoolean());
        assertEquals((byte) 0xFF, raf.readByte());
        assertEquals(0xFF, raf.readUnsignedByte());
    }

  /**
   * The largest value that fits into an unsigned byte.
   *
   * @since 13.0
   */
  public static final byte MAX_VALUE = (byte) 0xFF;

  private static final int UNSIGNED_MASK = 0xFF;

  /**
   * Returns the value of the given byte as an integer, when treated as unsigned. That is, returns
   * {@code value + 256} if {@code value} is negative; {@code value} itself otherwise.

import com.google.common.annotations.GwtCompatible;
import java.nio.charset.StandardCharsets;

/**
 * Static methods pertaining to ASCII characters (those in the range of values {@code 0x00} through
 * {@code 0x7F}), and to strings containing such characters.
 *
 * <p>ASCII utilities also exist in other classes of this package:
 *
 * <ul>
 *   <!-- TODO(kevinb): how can we make this not produce a warning when building gwt javadoc? -->

// TODO: update when package unicode captures more of the properties.
func isSeparator(r rune) bool {
	// ASCII alphanumerics and underscore are not separators
	if r <= 0x7F {
		switch {
		case '0' <= r && r <= '9':
			return false
		case 'a' <= r && r <= 'z':
			return false
		case 'A' <= r && r <= 'Z':
			return false
		case r == '_':
			return false
		}

            char ch = str.charAt(i);
            // handle unicode
            if (ch > 0xfff) {
                out.append("\\u").append(hex(ch));
            } else if (ch > 0xff) {
                out.append("\\u0").append(hex(ch));
            } else if (ch > 0x7f) {
                out.append("\\u00").append(hex(ch));
            } else if (ch < 32) {
                switch (ch) {
                    case '\b':