docs: public List<AddOn> getInstalledAddOns() {
          List<AddOn> installedAddOns = new ArrayList<>(addOns.size());
          for (AddOn addOn : addOns) {
              if (AddOn.InstallationStatus.INSTALLED == addOn.getInstallationStatus()) {
                  installedAddOns.add(addOn);
              }
          }
          return installedAddOns;
      }