@Override
        public boolean equals(final Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            final MaskHolder other = (MaskHolder) obj;
            return id == other.id;
        }
Wrap the mask with an ID value that can be used for equality checks in
the UI, to allow multiple rows with the same check box values
stroom-statistics/stroom-statistics-client/src/main/java/stroom/statistics/impl/hbase/client/presenter/StroomStatsStoreCustomMaskListPresenter.java