public String getDefaultPosition(String sdName) {
        SearchDefinition sd;
        if (sdName == null) {
            sd = unionSearchDefinition;
        } else if (searchDefinitions.containsKey(sdName)) {
            sd = searchDefinitions.get(sdName);
        } else {
            return null;
        }

        return sd.getDefaultPosition();
    }
Returns whether it is permissible to update this object
container-search/src/main/java/com/yahoo/prelude/IndexFacts.java