private Sizes extractValues(String value) {
        if (value != null) {
            try {
                return Sizes.create(Arrays.stream(value.split(","))
                        .map(String::trim)
                        .map(Long::valueOf)
                        .collect(Collectors.toList()));
            } catch (Exception e) {
                LOGGER.warn(e.getMessage());
            }
        }
        return Sizes.unlimited();
    }
Turn the {@link StatisticStoreDoc} into an {@link List<QueryField>} object
<p>
This builds the standard set of fields for a statistics store, which can
be filtered by the relevant statistics store instance
stroom-statistics/stroom-statistics-impl-sql/src/main/java/stroom/statistics/impl/sql/search/SqlStatisticSearchProvider.java