@VisibleForTesting static DatasetSplitId of(EntityId datasetId, long splitVersion, String splitKey) { final String datasetIdAsString = escape(datasetId.getId()); String compoundSplitId = SPLIT_ID_JOINER.join(datasetIdAsString, splitVersion, splitKey); return new DatasetSplitId(compoundSplitId, datasetIdAsString, splitVersion, splitKey); }