public static String toString(final byte[] b1, String sep, final byte[] b2) {
        return toString(b1, 0, b1.length) + sep + toString(b2, 0, b2.length);
    }
Joins two byte arrays together using a separator.

@param b1  The first byte array.
@param sep The separator to use.
@param b2  The second byte array.
stroom-bytebuffer/src/main/java/stroom/bytebuffer/hbase/Bytes.java