@Override
    public void negate() {
        char[] a = getString().toCharArray();
        for (int i = 0; i < a.length; i++) {
            a[i] = (char)-a[i];
        }
        setValue(new String(a));
    }
Sets the value of this result.

@param value The value to set.
@return This, to allow chaining.
searchlib/src/main/java/com/yahoo/searchlib/expression/StringResultNode.java