parseId_() {
    const vint = this.parseVint_();

    if (vint.length > 7) {
      throw new shaka.util.Error(
          shaka.util.Error.Severity.CRITICAL,
          shaka.util.Error.Category.MEDIA,
          shaka.util.Error.Code.EBML_OVERFLOW);
    }

    let id = 0;
    for (const /* byte */ b of vint) {
      // Note that we cannot use << since |value| may exceed 32 bits.
      id = (256 * id) + b;
    }

    return id;
  }
Parses an EBML ID from the parser's current position, and advances the
parser.
@return {number} The EBML ID.
@private