private void writeCGeoExtensions(@NonNull final Geocache cache) throws IOException {
        gpx.startTag(NS_CGEO, "cacheExtension");
        XmlUtils.simpleText(gpx, NS_CGEO, "assignedEmoji", String.valueOf(cache.getAssignedEmoji()));
        gpx.endTag(NS_CGEO, "cacheExtension");
    }
counter for exported caches, used for progress reporting
main/src/main/java/cgeo/geocaching/export/GpxSerializer.java