@Override
protected void writeToStream(DataOutput output) throws IOException {
int size = 0;
for (HeightMapData data : maps.values()) if (data.isValid()) size++;
ByteUtils.writeVLI(output, size);
for (Map.Entry<Integer, HeightMapData> e : maps.entrySet()) {
HeightMapData map = e.getValue();
if (map.isValid()) {
ByteUtils.writeVLI(output, e.getKey());
map.writeToStream(output);
} else Log.warn("Trying to propagate invalid map data %d", e.getKey());
}
}
