return this;
    public void init() {        //      Perhaps generalize on type HOW OFTEN IS THIS USED! Each ONCE ? TODO        if (!initialized) {            allUsers = getAllIds("experimenters", "attribute_id");            allImgs = getAllIds("images", "image_id");            allDss = getAllIds("datasets", "dataset_id");            allPrjs = getAllIds("projects", "project_id");            allCgs = getAllIds("category_groups", "attribute_id");            allCs = getAllIds("categories", "attribute_id");            userId = getOneFromCollection(allUsers); // Perhaps generalize on type HOW OFTEN IS THIS USED! Each ONCE ?            prjId = getOneFromCollection(allPrjs);            dsId = getOneFromCollection(allDss);            cgId = getOneFromCollection(allCgs);            cId = getOneFromCollection(allCs);            /*             * for example. should be done in sub-classes             *              *imgsPDI = getPercentOfCollection(allImgs, percent);             *imgsCGCI = getPercentOfCollection(allImgs, percent);             *imgsAnn1 = getPercentOfCollection(allImgs, percent);             *imgsAnn2 = getPercentOfCollection(allImgs, percent);             *dsAnn1 = getPercentOfCollection(allDss, percent);             *dsAnn2 = getPercentOfCollection(allDss, percent);             *             */        }    }