@Override
  public void writeBinary(Base64Variant bv, byte[] data, int offset, int len) throws IOException {
    BsonBinary binary = new BsonBinary(Arrays.copyOfRange(data, offset, offset + len));
    writer.writeBinaryData(binary);
  }
Delegates all streaming API to {@link BsonWriter}.
criteria/mongo/src/org/immutables/criteria/mongo/bson4jackson/BsonGenerator.java