code: @Override
  	public int size() {
  
  		if (allElementsInCache) {
  			return orderedCache.size();
  		} else {
  			int count = 0;
  			try (final RocksBytesIterator iterator = orderedBytesIterator()) {
  				while (iterator.hasNext()) {
  					iterator.next();
  					++count;
  				}
  			}
  			return count;
  		}
  	}
docs: This implementation comes at a relatively high cost per invocation. It should not be called repeatedly when it is
  clear that the value did not change. Currently this is only truly used to realize certain higher-level tests.