public GetSites clone() {
    GetSites c = new GetSites();
    c.filter = new Filter(filter);
    c.setLimit(getLimit());
    c.setOffset(getOffset());
    c.setSortInfo(getSortInfo());

    return c;
  }
  public static GetSites byActivity(int activityId) {
    GetSites cmd = new GetSites();
    cmd.filter().onActivity(activityId);

    return cmd;
  }
  public static GetSites byId(int siteId) {
    GetSites cmd = new GetSites();
    cmd.filter().addRestriction(DimensionType.Site, siteId);

    return cmd;
  }