public ModelFactory getFactory(Version version) {
        if ( ! factories.containsKey(version))
            throw new UnknownVespaVersionException("Unknown Vespa version '" + version +
                                                   "', cannot build config model for this version, known versions: " + allVersions());
        return factories.get(version);
    }
Returns the factory for the given version

@throws UnknownVespaVersionException if there is no factory for this version
configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelFactoryRegistry.java