is there a reason why this function returns a list of `Publication`s?

unpublishTracks(
    tracks: LocalTrack[] | MediaStreamTrack[]
  ): LocalTrackPublication[] {
    const publications: LocalTrackPublication[] = [];
    tracks.forEach((track: LocalTrack | MediaStreamTrack) => {
      const pub = this.unpublishTrack(track);
      if (pub) {
        publications.push(pub);
      }
    });
    return publications;
  }