public Utf8Array ascii7BitLowerCase() {
        byte [] upper = new byte[getByteLength()];

        for (int i=0; i< upper.length; i++ ) {
            byte b = getByte(i);
            if ((b >= 0x41) && (b < (0x41+26))) {
                b |= 0x20; // Lowercase
            }
            upper[i] = b;
        }
        return new Utf8Array(upper);
    }
Retuerns  the utf8 sequence as a Java string.
vespajlib/src/main/java/com/yahoo/text/AbstractUtf8Array.java