code: private int getFieldIndexes(ISyncHandler<?, ? extends ISyncableData> handler, String... syncNames)
  	{
  		int indexes = 0;
  		for (String str : syncNames)
  		{
  			ObjectData od = handler.getObjectData(str);
  			if (od != null)
  				indexes |= 1 << od.getIndex();
  		}
  		return indexes;
  	}
docs: Gets the indexes of the sync fields into a single integer.
  
  @param handler the handler
  @param syncNames the sync names
  @return the field indexes