public static Value create(byte[] value) {
        if (value == null) {
            return NixValue.instance();
        } else {
            return new Utf8Value(value);
        }
    }
A value type encapsulating a String in its UTF-8 representation.
Useful for lazy decoding; if the data is just passed through in
UTF-8 it will never be converted at all.

@author havardpe
vespajlib/src/main/java/com/yahoo/slime/Utf8Value.java