public ByteBuffer asReadOnlyByteBuffer()
    {
        final ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
        return byteBuffer.asReadOnlyBuffer();
    }
Constructs a new read-only {@code java.nio.ByteBuffer} with the same backing byte array.
protostuff-api/src/main/java/io/protostuff/ByteString.java