@Override
    public ResultPage<Meta> find(final FindMetaCriteria criteria) {
        final ExpressionMatcher expressionMatcher = new ExpressionMatcher(MetaFields.getAllFieldMap());
        final List<Meta> list = new ArrayList<>();
        for (final Entry<Long, Meta> entry : metaMap.entrySet()) {
            try {
                final Meta meta = entry.getValue();
//                final MetaRow row = new MetaRow(meta);
                final Map<String, Object> attributeMap = createAttributeMap(meta);
                if (criteria.getExpression() == null || expressionMatcher.match(attributeMap,
                        criteria.getExpression())) {
                    list.add(meta);
                }
            } catch (final RuntimeException e) {
                // Ignore.
            }
        }

        return ResultPage.createUnboundedList(list);
    }
This id is used to emulate the primary key on the database.
stroom-meta/stroom-meta-mock/src/main/java/stroom/meta/mock/MockMetaService.java