private Collection<IInstallableUnit> getInstalledWSO2Features(IProgressMonitor monitor)
      throws OperationCanceledException {
    SubMonitor progress = SubMonitor.convert(monitor, Messages.UpdateManager_23, 2);

    OperationFactory operationFactory = new OperationFactory();
    IQueryResult<IInstallableUnit> queryResult =
        operationFactory.listInstalledElements(true, progress.newChild(1));
    return filterInstallableUnits(
        WSO2_FEATURE_PREFIX, FEATURE_GROUP_IU_ID_SFX, queryResult, progress.newChild(1));
  }