matchAt(index, expected) {
    const state = this.#state;
    if (index + expected.length > state.length || index < 0) {
      return false;
    }
    for (let i = 0; i < expected.length; i += 1) {
      if (expected[i] !== this.byteAt(index + i)) {
        return false;
      }
    }
    return true;
  }
@param {number} index
@param {Uint8Array} expected
@returns {boolean}