public String toCanonicalString(String[] dimensionValues) {
        StringBuilder b = new StringBuilder();
        for (String dimensionValue : dimensionValues) {
            if (dimensionValue != null)
                b.append(dimensionValue);
            else
                b.append("*");
            b.append(",");
        }
        b.deleteCharAt(b.length() - 1); // Remove last,
        return b.toString();
    }
Represents a set of query profile variants (more or less) as they were declared -
a helper to produce config, which is also using the "declared" representation

@author bratseth
config-model/src/main/java/com/yahoo/vespa/model/container/search/DeclaredQueryProfileVariants.java