async postPeriodProcessing_(periods, isPatchUpdate) {
    await this.periodCombiner_.combinePeriods(periods, true, isPatchUpdate);

    // Just update the variants and text streams, which may change as periods
    // are added or removed.
    this.manifest_.variants = this.periodCombiner_.getVariants();
    const textStreams = this.periodCombiner_.getTextStreams();
    if (textStreams.length > 0) {
      this.manifest_.textStreams = textStreams;
    }
    this.manifest_.imageStreams = this.periodCombiner_.getImageStreams();

    // Re-filter the manifest.  This will check any configured restrictions on
    // new variants, and will pass any new init data to DrmEngine to ensure
    // that key rotation works correctly.
    this.playerInterface_.filter(this.manifest_);
  }
Handles common procedures after processing new periods.

@param {!Array<shaka.extern.Period>} periods to be appended
@param {boolean} isPatchUpdate does call comes from mpd patch update
@private