How to use the token-types.UINT8 function in token-types

const dataAtom = await this.tokenizer.readToken(new AtomToken.DataAtom(metaAtom.header.length - AtomToken.Header.len));

    if (dataAtom.type.set !== 0) {
      throw new Error('Unsupported type-set != 0: ' + dataAtom.type.set);
    }

    // Use well-known-type table
    // Ref: https://developer.apple.com/library/content/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW35
    switch (dataAtom.type.type) {

      case 0: // reserved: Reserved for use where no type needs to be indicated
        switch (tagKey) {
          case 'trkn':
          case 'disk':
            const num = Token.UINT8.get(dataAtom.value, 3);
            const of = Token.UINT8.get(dataAtom.value, 5);
            // console.log("  %s[data] = %s/%s", tagKey, num, of);
            this.addTag(tagKey, num + '/' + of);
            break;

          case 'gnre':
            const genreInt = Token.UINT8.get(dataAtom.value, 1);
            const genreStr = Genres[genreInt - 1];
            // console.log("  %s[data] = %s", tagKey, genreStr);
            this.addTag(tagKey, genreStr);
            break;

          default:
          // console.log("  reserved-data: name=%s, len=%s, set=%s, type=%s, locale=%s, value{ hex=%s, ascii=%s }",
          // header.name, header.length, dataAtom.type.set, dataAtom.type.type, dataAtom.locale, dataAtom.value.toString('hex'), dataAtom.value.toString('ascii'));
        }
        break;

case 'CMPR': // 3.2.3 Compression Type Chunk
          const compressionIdCode = (await this.tokenizer.readToken(FourCcToken)).trim();
          const count = await this.tokenizer.readToken(Token.UINT8);
          const compressionName = await this.tokenizer.readToken(new Token.StringType(count, 'ascii'));
          if (compressionIdCode === 'DSD') {
            this.metadata.setFormat('lossless', true);
            this.metadata.setFormat('bitsPerSample', 1);
          }
          this.metadata.setFormat('codec', `${compressionIdCode} (${compressionName})`);
          break;

        case 'ABSS': // 3.2.4 Absolute Start Time Chunk
          const hours = await this.tokenizer.readToken(Token.UINT16_BE);
          const minutes = await this.tokenizer.readToken(Token.UINT8);
          const seconds = await this.tokenizer.readToken(Token.UINT8);
          const samples = await this.tokenizer.readToken(Token.UINT32_BE);
          debug(`ABSS ${hours}:${minutes}:${seconds}.${samples}`);
          break;

        case 'LSCO': // 3.2.5 Loudspeaker Configuration Chunk
          const lsConfig = await this.tokenizer.readToken(Token.UINT16_BE);
          debug(`LSCO lsConfig=${lsConfig}`);
          break;

        case 'COMT':
        default:
          debug(`Unknown sound-property-chunk[ID=${sndPropHeader.chunkID}, size=${sndPropHeader.chunkSize}]`);
          await this.tokenizer.ignore(sndPropHeader.chunkSize);
      }
      const remaining = sndPropHeader.chunkSize - (this.tokenizer.position - p0);
      if (remaining > 0) {

switch (sndPropHeader.chunkID.trim()) {

        case 'FS': // 3.2.1 Sample Rate Chunk
          const sampleRate = await this.tokenizer.readToken(Token.UINT32_BE);
          this.metadata.setFormat('sampleRate', sampleRate);
          break;

        case 'CHNL': // 3.2.2 Channels Chunk
          const numChannels = await this.tokenizer.readToken(Token.UINT16_BE);
          this.metadata.setFormat('numberOfChannels', numChannels);
          await this.handleChannelChunks(sndPropHeader.chunkSize - Token.UINT16_BE.len);
          break;

        case 'CMPR': // 3.2.3 Compression Type Chunk
          const compressionIdCode = (await this.tokenizer.readToken(FourCcToken)).trim();
          const count = await this.tokenizer.readToken(Token.UINT8);
          const compressionName = await this.tokenizer.readToken(new Token.StringType(count, 'ascii'));
          if (compressionIdCode === 'DSD') {
            this.metadata.setFormat('lossless', true);
            this.metadata.setFormat('bitsPerSample', 1);
          }
          this.metadata.setFormat('codec', `${compressionIdCode} (${compressionName})`);
          break;

        case 'ABSS': // 3.2.4 Absolute Start Time Chunk
          const hours = await this.tokenizer.readToken(Token.UINT16_BE);
          const minutes = await this.tokenizer.readToken(Token.UINT8);
          const seconds = await this.tokenizer.readToken(Token.UINT8);
          const samples = await this.tokenizer.readToken(Token.UINT32_BE);
          debug(`ABSS ${hours}:${minutes}:${seconds}.${samples}`);
          break;

get: (buf, off): IId3v1Header => {
    const header = new Id3v1StringType(3).get(buf, off);
    return header === "TAG" ? {
      header,
      title: new Id3v1StringType(30).get(buf, off + 3),
      artist: new Id3v1StringType(30).get(buf, off + 33),
      album: new Id3v1StringType(30).get(buf, off + 63),
      year: new Id3v1StringType(4).get(buf, off + 93),
      comment: new Id3v1StringType(28).get(buf, off + 97),
      // ID3v1.1 separator for track
      zeroByte: Token.UINT8.get(buf, off + 127),
      // track: ID3v1.1 field added by Michael Mutschler
      track: Token.UINT8.get(buf, off + 126),
      genre: Token.UINT8.get(buf, off + 127)
    } : null;
  }
};

get: (buf, off): IId3v1Header => {
    const header = new Id3v1StringType(3).get(buf, off);
    return header === "TAG" ? {
      header,
      title: new Id3v1StringType(30).get(buf, off + 3),
      artist: new Id3v1StringType(30).get(buf, off + 33),
      album: new Id3v1StringType(30).get(buf, off + 63),
      year: new Id3v1StringType(4).get(buf, off + 93),
      comment: new Id3v1StringType(28).get(buf, off + 97),
      // ID3v1.1 separator for track
      zeroByte: Token.UINT8.get(buf, off + 127),
      // track: ID3v1.1 field added by Michael Mutschler
      track: Token.UINT8.get(buf, off + 126),
      genre: Token.UINT8.get(buf, off + 127)
    } : null;
  }
};

get: (buf, off) => {

    return {
      crc: Token.UINT32_LE.get(buf, off),
      streamVersion: Token.UINT8.get(buf, off + 4)
    };
  }
};

private async readVariableSizeField(len: number = 1, hb: number = 0): Promise {
    let n = await this.tokenizer.readNumber(Token.UINT8);
    if ((n & 0x80) === 0) {
      return {len, value: hb + n};
    }
    n &= 0x7F;
    n += hb;
    return this.readVariableSizeField(len + 1, n << 7);
  }
}

private async parseEbml(level: number, posDone: number): Promise {
    const ebml: IEBML = {segments: []};
    while (this.tokenizer.position < posDone) {
      const e = await this.readElement();
      switch (e.id) {
        case 0x18538067:
          const segment = await this.parseSegment(level + 1, this.tokenizer.position + e.len);
          const duration = segment.segmentInfo.duration * segment.segmentInfo.timecodeScale / 1000000000;
          this.metadata.setFormat('duration', duration);
          ebml.segments.push(segment);
          break;
        case 0x4286:
          ebml.version = await this.tokenizer.readNumber(Token.UINT8);
          break;
        case 0x42f7:
          ebml.readVersion = await this.readUint(e);
          break;
        case 0x42f2:
          ebml.maxIDWidth = await this.readUint(e);
          break;
        case 0x42f3:
          ebml.maxSizeWidth = await this.readUint(e);
          break;
        case 0x4282:
          ebml.docType = await this.readString(e);
          break;
        case 0x4287:
          ebml.docTypeVersion = await this.readUint(e);
          break;