@Override
    public void clear() {
        feeds.clear();
        types.clear();
        types.addAll(STANDARD_TYPES);
        metaMap.clear();
        currentId = 0;
    }
Turns a data row object into a generic map of attributes for use by an expression filter.
stroom-meta/stroom-meta-mock/src/main/java/stroom/meta/mock/MockMetaService.java