public static byte[] toBytes(ByteBuffer buffer, int offset, int length) {
        byte[] output = new byte[length];
        for (int i = 0; i < length; i++) {
            output[i] = buffer.get(offset + i);
        }
        return output;
    }
Copy the given number of bytes from specified offset into a new byte[]

@param buffer input bytebuffer to read
@param offset input offset where Bytes are
@param length the number of bytes to read
@return a new byte[] containing the bytes in the specified range
stroom-bytebuffer/src/main/java/stroom/bytebuffer/hbase/ByteBufferUtils.java