private void writeBuckets(Writer w, ImmutableSortedMap<Integer, Bucket> buckets)
throws IOException {
for (Entry<Integer, Bucket> entry : buckets.entrySet()) {
Integer bucketIndex = entry.getKey();
Bucket bucket = entry.getValue();
print(w, TreeNode.BUCKET.name());
print(w, "\t");
print(w, bucketIndex.toString());
print(w, "\t");
print(w, bucket.id().toString());
print(w, "\t");
Envelope env = new Envelope();
env.setToNull();
bucket.expand(env);
writeEnvelope(w, env);
println(w);
}
}
