public long setGhostState() {
        long sum = 0;
        final int nc = microCaches == null ? 0 : microCaches.length;
        for (int i = 0; i < nc; i++) {
            final MicroCache mc = microCaches[i];
            if (mc == null) {
                continue;
            }
            if (mc.virgin) {
                mc.ghost = true;
                sum += mc.getDataSize();
            } else {
                microCaches[i] = null;
            }
        }
        return sum;
    }
cache for a single square

@author ab
main/src/main/java/cgeo/geocaching/brouter/mapaccess/OsmFile.java