public IndexVolume indexVolume() {
        if (_indexVolume == null)
            _indexVolume = new IndexVolume(this, Keys.INDEX_SHARD_FK_VOLUME_ID);

        return _indexVolume;
    }
Get the implicit join path to the <code>stroom.index_volume</code> table.
stroom-index/stroom-index-impl-db-jooq/src/main/java/stroom/index/impl/db/jooq/tables/IndexShard.java