docs: protected String getMultiGetQueryCacheQuery(EntityKey[] keys) {
  		int numberOfKeys = keys.length;
  		String query = multiGetQueryCache.get( numberOfKeys );
  		if ( query == null ) {
  			query = createMultiGetOnMultiplePropertiesId( numberOfKeys );
  			String cached = multiGetQueryCache.putIfAbsent( numberOfKeys, query );
  			if ( cached != null ) {
  				query = cached;
  			}
  		}
  		return query;
  	}