private byte[] getBytesFromByteBuffer(ByteBuffer byteBuffer) {
        if (byteBuffer == null) {
            return null;
        }

        byteBuffer.rewind();
        byte[] bytes = new byte[byteBuffer.remaining()];
        byteBuffer.get(bytes);
        return bytes;
    }
Pass-through converter for raw byte data.
<p>
This implementation currently does nothing with the topic names or header keys.
connect/runtime/src/main/java/org/apache/kafka/connect/converters/ByteArrayConverter.java