@Override
    public EffectiveMetaSet findEffectiveData(final EffectiveMetaDataCriteria criteria) {
        final Builder builder = EffectiveMetaSet.builder(criteria.getFeed(), criteria.getType());

        try {
            metaMap.values()
                    .stream()
                    .filter(meta ->
                            NullSafe.test(criteria.getType(), type -> type.equals(meta.getTypeName())))
                    .filter(meta ->
                            NullSafe.test(criteria.getFeed(), feed -> feed.equals(meta.getFeedName())))
                    .forEach(meta -> builder.add(meta.getId(), meta.getEffectiveMs()));

        } catch (final RuntimeException e) {
            System.out.println(e.getMessage());
            // Ignore ... just a mock
        }
        return builder.build();
    }
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