@Override
 public void addBinary(Binary value) {
   holder.buffer = buf = buf.reallocIfNeeded(value.length());
   buf.setBytes(0, value.toByteBuffer());
   holder.start = 0;
   holder.end = value.length();
   writer.write(holder);
 }
 @Override
 public void addBinary(Binary value) {
   holder.buffer.setBytes(0, value.toByteBuffer());
   writer.write(holder);
 }