public void printZoomHeaders() {

        // note if successfully read - should always be correct
        if(zoomLevelHeaders.size() == zoomLevelsCount)
            log.debug("Zoom level headers read for " + zoomLevelsCount + " levels:");

        else
            log.error("Zoom level headers not successfully read for "
                    + zoomLevelsCount + "levels.");

        for( int index = 0; index < zoomLevelHeaders.size(); ++index) {

            // zoom level headers print themselves
            zoomLevelHeaders.get(index).print();
        }

    }