showFactionVisualsForFactionId(factionId, generalId) {
    if (factionId != null) {
      const factionData = SDK.FactionFactory.factionForIdentifier(factionId);
      this.deckStatsLayer.setFactionName(factionData.name);
    } else {
      this.deckStatsLayer.setFactionName('');
    }
    this.showBackgroundCrestForFactionId(factionId);
    this.showPortraitForFactionId(factionId, generalId);
  }
Shows visuals for a general and faction, or clears current visuals if none provided.
@param {String} [factionId=null]
@param {String} [generalId=null]